if you are looking for subs, i would highly recommend the HIFONICS WARRIOR 12's or 15's (very good speakers). one 12 inch HIFONICS WARRIOR and a amp is all you really need for the small surface area that your trunk has. that is all i have and it is plenty for me and it produces a good bang when the bass hits
no i have subs already...2 alpine type Rs 12"
and need speakers but i dont know what to get and dont know what amp to pair that up with
check the crutchfield link i gave you. those are speakers that will definately fit the celica (won't be too deep).
personally, i'd get component speakers. more expensive, but well worth it when it comes to sound quality. crossovers, removable tweeters,...its awesome.