Join Date: Oct 2006
Location: Fishers Indiana
Bikes: Longbikes Slipstream
I think first choice will be long or short wheelbase, but it will depend on your commuting conditions. Heavy, multi-lane, urban riding in a congested zone will say SWB. Wide open spaces with low traffic and congestions will say LWB, and LWB will likely be slightly more comfortable over time. Think about what kind of manuvering you've done while on your route, and how often. Probably many will suggest a trike, but I'm not one of them as I like thinking about only one sight line for the wheels instead of three.
Steering is more of a personal choice. OSS will be slightly faster and perhaps have more convenience for hanging stuff in front of you (water, bell, computer, etc.). USS is, well, USS and in my opinion more comfortable, but seems to be a minority position.
Rear wheel needs to be at least 26/559 size as it takes a hammering. Bigger is better. More spokes are better. Deeper-V rim is better. Larger front wheels are said to be faster, but I'd be more inclined for the 20 inch so you can have a seat pan height that allows a foot down while fully resting in the seat, so that when you stop for a red light or stop sign, you just flat foot on one side and leave the other one clipped in for the next start.
If you have much vertical (probably not on the gulf coast?) then weight will play a larger factor, but you're going to have weight in rack, fenders, lighting, panniers by the time you're fully outfitted, plus your daily load (for me, work clothes and shoes, rain gear, parts and tools, shower kit, laptop, etc).
I haven't found commuting that fast over time, but I also don't care as I'm well used to my 25 mile round trip, almost 5,000 mile annual mileage. I probably ride 15-18 mph on average with a peak of 25-30 on one slight incline, but only see 13-15 on elapsed time due to red lights and stop signs.
I'll PM you my model choices, so I don't get killed for missing someone else's favorite ride.