It depends on your definition of "small mods". I think at your level, you're going to be looking at headwork (go to a reputable head porter!), cams/springs/retainers, Indy intake manifold, cam gears. Taking weight out of the car will also make your car faster is every way, and doesn't cost a thing. Being that you have about the heaviest G1 Neon, you could take a bunch of weight out.
Also, why haven't you gone with an aftermarket PCM, like the MP unit? It's like $200 (or so), and is very easy to install.