advice on performance mods

That's pretty broad. If you want some stuff to do yourself, you can go with basic bolt-on mods. Throttle body, intake manifold, header, exhaust, and intake are considered bolt-ons. You could also put nitrous on yourself if you are a hands-on type of person. Nitrous kits are cheap compared to other forms of FI (yes, nitrous is forced induction.) If you're planning on paying someone to do stuff, but don't want a turbo or supercharger, you can go with a set of cams, which you usually need to upgrade your valvetrain (valve springs, retainers), you can get a set of higher compression pistons also. You can bore the block over and port and polish the head. You can stroke your engine (pretty expensive though), and you can also upgrade clutch and flywheel which will increase performance. You can invest in a nice set of springs for performance in the twisties. You can invest in some sticky tires, too. Hope that helps a little in your decision.