Pardna', as you said, it's going to be difficult to compare with the conditions to which you are accustomed. To adequately do that, you'd most likely have to hit the Flower Garden Banks National Marine Sanctuary, which is 110 miles off the Texas Coast. There, vis is similar to what you see in Florida, and the benthic cover probably exceeds what you've seen back home. But that doesn't meet your parameters of "3 or 4 hours". That said, it's necessary to remember where you are...miles inland on the Texas plains. There are a couple of places you and your buddy might consider, though, and even find interesting.
If vis is what you're after, try Balmorhea State Park, Balmorhea Texas. It's far (and I mean REALLY far, which again probably violates your drive rule) southwest Texas but it features stunning visibility. However, it's actually an overgrown swimming pool fed by many natural springs. Max depth is about 22 feet, but the water is a constant 72 degrees year round, you can watch the water bubble up from dozens of underwater springs, and there is an abundance of fish and other critters to see. Facilities are great (hot showers, etc...) and the diving is, of course, very relaxed.
And from there, the vis issue clouds up a LOT (no pun intended...well, that's not true. It was completely intentional). There is another spring fed facility in San Marcos (Aquarena Center), but diving there is restricted to those who have taken their science diver course, and then is governed to what they need done (no strictly recreational diving).
After that, you're probably looking at lakes with conditions similar to Lake Travis in the Austin area. Vis is typically 10-15 feet on good days, and they will probably be pretty cool this time of year. Lake Possum Kingdom (about 70 miles west of the Dallas-Ft. Worth metroplex), 288 Lake and Mammoth Lake (near Houston), and two lakes in southern Oklahoma (Lake Murray and Lake Elmer Thomas) are all about the same in vis and features. There is a good rock quarry near Terrell, Texas (Clear Springs Scuba Park) that has good facilities, but right now the vis is about the same as area lakes.
There might be a few I've missed, but those are the main ones, and I'm not sure any of them will meet your parameters or impress you, but that's the "charm" of local diving...one gets to experience something new and gain a greater appreciation for what others routinely dive. Hey, we don't call this the "Texas Swamp Divers" forum for nothing! Have fun and welcome to Texas!
