When it comes to the up-pipe, you will be stuck with OEM if you want to keep the cat. However, there really isn't a reason you need one there. In fact, imo a pre turbo cat is more harmful than benefitial. If it desides to fall apart, your turbo is getting a face full of metal pieces. You should just get a OEM STI uppipe or a Bosal. Both look 100% stock and include heatshields, EGT sensor bung, and a unique flex section that doesn't fail as much as a traditional flex.
When it comes to the downpipe, i don't know how strict Texas is for emissions, but if you do aftermarket, Perrin makes a two piece downpipe that is emissions compliant (except for CARB). Its a pricey piece and would require a tune, but it's a great DP. Other than that, if TX doesn't do sniff tests, you could always do a cated DP and do an o2 spacer to take care of the CEL (that is if you throw a code). Aside from that, you can buy a used dp from someone on the forums, or you could always just gut yours and run the previously mentioned o2 spacer.