I was in Austin last week and swung by GTU. Pilot's choice looks like a pretty good place for rental. They have a ton of Tomahawks which are under $100/hour, which for a guy who pays $130-140/hour for a 172 is considered dirt cheap. They also have Warriors and 172RGs. Planes look well maintained and the folks who work there seem friendly. People say checkouts there are fast and cheap as well.
It took me and my buddy less than 20 minutes to drive from North Austin to GTU, just avoid the commute hours and you should be fine.
Have you flown a Tomahawk before? These Traumahawks are pure VFR. Check the avionics before each flight. When I was there, we had one with a functional VOR. Not all are stickered inop - despite my best efforts. One had a functional GPS that was out of date. Several had transponder issues. The one with the green paint was never flown. I worked at PCA for almost a year and saw it flown one time. The instructors were terrified of it because nobody had ever been able to get >250fpm climbs. I think the glide is 6:1, so be ready to pick a field about half the distance that you'd normally pick in a 172. If you want to just mess around in the pattern or show your girlfriend the lake, those birds will work. Otherwise, I'd look at something else.
I loved the Archers/Warriors. If I were renting from PCA, I would only fly those or the Duchesses. The 172RGs are great for getting a rating, but again the avionics suck hard and they're just old and beat to .
They have an Eclipse too, but I refused to fly it after I found out that the engine quits anytime the electrical fuel pump is not on (should not be necessary). It is also the worst hot starting airplane maybe ever.
The Duchesses are good birds and could not be beat for the price last year. Then Beth raised the price with fuel and to my knowledge has not brought it back down. It's still not a bad place to rent the twins. If you get your rating, expect at least 10 hours.
On that note...While I was there, the instructors were thorough. Very thorough. I thought it was great, but this is not the school to go if you think "Oh yeah I need 3 hours for my CMEL add on." I don't know who is still there, but Paul, Chuck, and Lou were all outstanding instructors.
If you live anywhere near the east side, take the tollway. I could get from Bergstrom to GTU in 35 minutes on 130. From the westside the loop 1 toll is great, but only gets you to Round Rock.