Best Genset controller (buy, costs, store)

[Booman2k14]

Round and round we go. I can't believe that I'm the only one that has come up against this situation, so I've come here for the best you got.
I have:
1. 200 amp service with a service disconnect on the meter box
2. Generac Powermanager LTS service rated ATS that sends +12VDC, ground, and genstart signal, along with
mains sensing signals.
3. Kubota GL6500S diesel (portable) that requires timed preheat for the glow plugs, fuel solenoid, crank, and
shutdown signals.

What is my best bang for the buck in a generator controller.
I way out of my comfort zone here, but it seems that the "experts" I've talked to are as well.
I've been advised to replace #1, #2, or both and that is just not an option. Time, $, and location prohibit.
I am shying away from Deep Sea controllers because of their origin but have not ruled them out.
Any help is appreciated.

[Nor'Eastah]

You are in the deep blue sea, as I am (we are off-grid). It was just last year when I came up against the daunting task of "sizing" a complete off-grid solar system to run our household -- battery bank, inverter, generator, solar panel wattage, etc. I had to do my own due diligence (as you will have to), online as the "experts" disagreed with each other too frequently. The problem I ran into, is that most solar power systems are grid-tied; those that are not (marine and RV systems) are much smaller than what a normal household would require. So I had to educate myself. You won't find any fast answers here.

What I can tell you, is that you really should install a battery bank. It's the farthest thing from your mind, I know. But in the event of a power outage, you will be running the generator(s) 24/7 until power is restored. That is wasteful of fuel, which can be costly. With a battery bank, you can store that power, running the genset for just 30-60 minutes a day, and running your household for the rest of the day off the battery bank. This is a closely-guarded secret that few know. People just buy generators and run them 24/7 during a power outage - which can last 2-3 weeks - and it costs them a ton of $$$ in fuel. With a battery bank, you can even save on your regular grid power bill, just by running the genset 30-60 mins a day. Maybe that's why the info is not well known; the power companies have to be hating this. It would decimate their revenues.

[MrRational]

Generally... the BEST generator controller will be the one sold by the generator maker.

If YOU have some specific complaint with their defaults...
or need to add/change something specifically about those defaults...
address that as a "layer" on top of or along side those defaults.

in short... avoid reinventing the wheel.