upping a 98 eclipse... need assistance plz

I have a 1998 mitsubishi eclipse 2.0L GS
(im sure its a GS, but how can you definately make sure if its a GS or an RS??)

i want to put some money onto performance parts... where should i start, and what would be really worth buying??
i already have a short ram CAI and DENSO Iridium plugs... and bosch wires, which im gonna change for NGK soon...

WHAT SHOULD I INVEST!!! SUGGESTIONS PLEASE!!!

well, on the back of the car should be GS or RS... or check the title...

Now, that doesn't really matter as they both share the 420a engine (from a Dodge Neon)...

I would suggest going the natural N/T(N/A) route...
Start with intake and exhaust(at least muffler, if not cat-back)... ignition, underdrive pulleys... or even remove the ps/ac belt (that's what I did to my RS)... I might also suggest when doing the exhaust to go ahead and get headers...
check out, dsmtuners.com... I believe they have a 2g NT upgrade path on their site...

Edit: Here's the link to it: http://www.dsmtuners.com/sub.php?page=2gntupgrades

What are your goals? If you are happy with 15-16 second quarter miles then do the basic intake, header, exhaust, weight reduction, maintainance, and other little stuff like crank pulley and maybe a short throw. If you want to go any faster than that, I would recommend you get a different car, I have a hard time justifying dumping a several grand into a 420a to run atleast mildly respectable 1/4 ET's when a 1g turbo could do it much easier and much more cost efficient.

You could always turbo but you have to build the internals too. You could stroke it or spray it too. Basic performance mods will beef it up. With all the bolt ons I have it's nice and fast, but you have to do it right. Just adding any ole mods will not neccesarly make it quick. You ahve to make sure they all work together. I would say go with a full exhaust first. Header, high flow cat, and cat-back. Great performance gains from that. Plugs, wires, and coil pack will also help out quite a bit too, especially for gas mileage.