The 5s is a good engine but doesn't have much power. You could build one up a little with cams and some bolt-ons but it'd probably end up costing you around $2k. Because you're in texas you don't have to worry as much about smog checks so I'd say just try and find a 3 generation 3sge. I think they put out some decent power and are affordable if you can find one. Honestly a turbo swap can cost less than $1500 if you do the work yourself. Although the turbos aren't good for auto-x (more drag oriented). Although if you're concerned about classing in auto-x you would need to have stock internals...I'm not sure if it matters what engine you have (5s or 3s). Honestly the best route for you would probably be the 3sge. I'd do it if I wasn't in California.
This member might be selling a 3rd gen. 3sge.
Sell my 3sge?