I've been thinking about getting a cold air intake for my 98 gs eclipse, can anyone tell me what brand would be best???

 

Short ram pipe from e-bay, and a K&N filter. That is all.

 

you won't see much of a differnece whether it's ebay or AEM/Injen so i'd just buy a cheap CAI from ebay. grab a K&N filter like Rob said and slap it on the end. i was lucky enough to find a used AEM CAI for mine for 100 bucks.
you will hear a lot of people warn you about hydrolock (filter getting submerged in water and sucking water into the car) i ran mine for over 2 years and never hada prolem at all. but then again i wasn't driving through anything deeper than about 6 inches. if you are in a high water level location than i'd either go w/ a short ram or get a bypass valve for the intake.