if you want cheap, wal-mart sells a speaker line called lighning audio, now i know what your thinking whats this kid doing telling me to go to wal-mart. a friend of mine bought them for his cavalier 6.5's, and they have a really strong bass woofer, the rest of the speaker isnt as good, but imo they sound better than pioneers and will be able to handle the stock deck, as far as bass tubes go, get a bazooka el, its a little over a hundred dollars, and its more bass than youll ever need from the stock deck. i have my 5.5's replaced with a set of pioneers that sound better than the stock ones but ^^^ is right they dont sound that great, i also have a bazooka el in my trunk, i have a perfect mix from my stereo and all my components cost me less than 200$