firstly, i dont think any kid is too young for their first dog, as long as your willing to supervise, never let dog and child be alone together, socilize puppy liek crazy and teach child acceptable behaviour around the dog (no hugging, not too much roughhousing ect...)
secondly...
a dog of any kind would do fine with that kind of work schedual...
do NOT let the fact you both work put you off or anyone make you feel bad about having to work, MILLIONS of dogs of all breeds live happy lives with "working parents"
most dogs will sleep while your not home then be ready to play when you are, they are adaptable creatures, and while i do agree some dogs are more "velcro" than others unless you get a dog with server seperation anxiety, being alone for a few hours a day is NOT going to break its heart.
however housebreaking a puppy is going to be tough...puppies have tiny bladders SOO my suggestion to you, especially since your looking into smaller breeds would be to litterbox or puppy pad train...
during the day you would have puppy in a small area, a crate with a small playpen attatched or something similar, or in a pinch a kitchen or bathroom, bed goes in the crate, dogs dont like to potty where they sleep, then you put out a wee wee pad the pads are treated with an attractant...
when your not home puppy has acess to the wee wee pads 24/7...when you are home however puppy gets taken outside to potty every hour to start off with...
the idea being you 1: want to teach him that the pads are for emergencies only
and 2: you may want to eventually wean him off the pads as he becomes better able to hold his bladder, so by teaching him outside is also for potty (rather than ONLY using the pads) puppy is goign to be less confused later on...
our chihuahuas are all pad trained because my father owns a boat, ts impossible to find grass when your out on the ocean lol....
but its great for cold winters, apartments and working families...
in terms fo breeds, you say baby does fine with other family members poodle and ****zu...
so this is a good start, NO breed is truly hypoalergenic, (only hairless breeds are considered even close), but if hes not sensitive to the hair coated type breeds, its a good starting point...
personally i wouldnt do a toy poodle, they tend to be too delicate for kids and prone to a napoleon complex...
a mini however (next size up) might be a good choice if your not worried about grooming, poodles require ALOT of grooming...
infact, ALL "low allergen" tend to be higher maintence in the grooming department.
****zu typically make wonderfull family pets, keep in a teddy bear or puppy cut for ease, still some grooming involved but a little easier than the poodle.
bichon is a good choice, again typically good with gentle kids, considered a low allergen breed, not too tiny as to be breakable but still a small breed. less grooming than a poodle, more than a shi-tzu.
maltese are nice dogs, though ive found they can be very energetic, very sweet, about the same grooming requirments as a shi-tzu
i HAVE to suggest the chinese crested (a powderpuff could be a perfect match, hairless need more skin care and certianly arnt for everyone) great size, not bad on the grooming (powderpuff a bath twice a month and comb through every day and a trim around the eyes is all thats realy needed)
i have cresties, never thought about them as the breed for me untill i fostered ruby...well ruby never left and now i have 2 and am plannign to add a third in the next year or so...
they are amazing little dogs, very sweet, very athletic, very bonded to their people. and both the hairless and the puff are usually good for allergy sufferers)
Havanese, about the same size and upkeep as the maltese very cute, very sweet
lhasa apso, another "hair breed" simialr to the ****zu and maltese in terms of upkeep
lowchen, cute, tend to be higer energy than some of the typicall "low allergen" breeds the few ive met are wonderfull with kids...and no there not born with a nekkid butt so you dont have to have them clipped that way lol.
American Hairless Terrier (like hairless cresties, truly hypoalergenic) less skin care upkeep than the cresties, but also no fancy furnishings (though many have mohawks) the hairless breeds deifnatly take an aquired taste, but if you want tryly hypoalergenic, hairless is the way to go...no coat = no sheeding, no hair means nowhere for dander to hide...so it cant buld up and agrivate allergies either...
the AhT is the ONLY terrier i perosnally would suggest for a younger family first time dog owners, they are typically more mellow than the rat terrier (their coated cousins, the aht is actualy a mutation in the rat terrier, but for some reason the hairless seem to be much more mellow overall)
terriers i would ruel out completly, high energy, high drive and not typiclaly good with YOUnG kids...
of all those suggestions id say a crestie, aht or shi-tzu might be the best bets...
i also suggest finding breders of any of the breed syour interested in and having meet and greets with your kid, something that doesnt bother 1 persons allergies might bother anothers...
also i am NOT anti breeder...if you want to rescue, rescue, if you want a puppy from a breeder use a breeder but please get a GOOD breeder, if youd like help figuring out if a breeder s good or not, dont hesitate to ask...
do nOt buy a puppy from a pet store, do nOT buy a puppy off craiglist, do NOT buy a puppy out of the local classifeids or that guy selling dogs in the walmart parking lot...
and just because they say "akc/ckc" ect doesnt mean they are good breeders...akc is a registry not a policing system (same goes for ANY registry, they are simply people who keep track of lineages, nothign more nothing less...)
many good breeders often have slightly older pups available too (in the 4-8month range) puppies they held back in hopes of show prospect or returned for a reason not its own fault (divorse is common) because good breeders take back any puppy they produce for any reason... these puppies are often already started on training housebreaking and well socilized, so this might be an excelent path to follow for your first dog, youd still get a young puppy from a good breeder but might already be passed the most difficult puppy stages
if you need any help, dont hesitate to ask!