do you have an amp?
If not you may actually lose volume, OEM speakers are way more efficent tham aftermarket so at the same low wattage the new ones might even be quieter. I would say get some thing that either pushes 4 x 50 or 2 x 100 and then it'll be like a whole different world
pioneer would be on the bottom of my list, i currently have boston 6.5 pro series components in the front of my camry with nx97 6x9s in the rear. i used to have eclipse 6x9s that were damn good but i just needed some rear speakers with more highs to them. infinity's are pretty good also.
thanks again for all the replys, the stockers are 6 ohms so I'd assume that with 4 ohms and 93 db sens replacements would at least equal the sound level output.. I've got several amps lying around but am not sure if I want to go to the trouble yet. The 6 spkr system that came with the 6 disc in dash surprised me, it actually vibrates the mirrors while still giving clean sound-no clipping.