From Richmond (like the Pecan Grove area) you'd go in on 59, I'd guess that would be vastly different at 6am than 8am. 59 mainlanes get pretty hairy around 8AM for sure.
From Cinco Ranch on I-10, it would be pretty easy, and about a 30-40 minute commute door to door. I take it all the time and I am at the Beltway and I-10 and it takes me about 20 minutes at 9AM, as long as there are no accidents!
With either route, I recommend you take the Park-n-Ride. No paying for parking, no sitting in traffic (HOV lane instead!). The Park-n-Ride for 59 would be the 297 and the Park-n-Ride for I-10 would be the 298. Check
METRO - Metropolitan Transit Authority of Harris County, Houston, Texas for more info.
Good luck!