well, the amp you need is just any 4 channel amp.
you want something with low wattage and high DB.
i am selling an amp if you are interested, but i can give you a heads up on what to look for. the connection you have at best buy better work there so they can get a sick associates discount.. haha.. otherwise, go to ebay.
the first thing you want is a name-brand amp. anything else will sound like ****, blow your speakers, and/or not be loud at all.
the brand amps you wanna look at are:
Alphasonik
Alpine
Audiobahn (for subs)
Bazooka
Bose
Clarion
Crossfire (personal fav)
Crunch
Dual
Infinity
JBL
JL audio
JVC
Kenwood
Kicker
Optimus
Pioneer (some of the high end stuff is okay)
Rockford Fosgate
Sony
Swiss audio (rare, simple, but sound good)
there are a few others, those are just the ones that i know off hand.
what you want is a nice 4 or 6 channel amp with anything over 100 DB, and a wattage of less then 75 watts RMS (really should be like 50 watts rms or less) but that gets hard to find, and very expensive.
the sony amp i have for sale was $350 new, but is 30 watts RMS per channel at 6 channels. and the amp it replaced was a crossfire amp at 35 watts per channel at 4 channels. both with over 100 DB. (and so loud, it would turn heads. haha, seriously, you can hear my car over 4 blocks away, and thats is not just the sub that you hear)
for your speakers, you need an amp that will preform, if it does not have MORE THEN 95 DB, it is JUNKKKKKK. if it has more then 75 watts RMS, it will BLOW YOUR SPEAKERS.
watts mean nothing when you want a loud system. DB is how loud that amp is. what happeneds is that when you shop amps, you see 1000 watt amps, with 80 DB.. meaning, it needs to push 1000 watts before it is loud. but, instead, if you would buy a 250 watt amp with a DB of 100, it will be jsut as loud, and you will never blow your speaker.
the same is true for a 4/6 channel amp. you need something that will be loud, and not break your speakers.. a 35 watt amp can be plaied as loud as you want and it will NEVER break your speakers, but if it has a DB of less then 95, it will not be loud.
its kinda easy to figure out once you work with amps for awhile, but remember, all you want is something that is 100 db, and around 50 watts per channel RMS or less, max watts mean nothing. for a sub amp, you want something that is 95 DB or more, and you match the wattage with your sub. like, my alpine type r sub is 250watts rms, and my bazooka amp is 300 watts RMS. well, i turned down the power half way to protect it. its pushing a max of 225 watts rms so it will never blow the sub nomatter how loud i push that sub. that poor little sub shakes my car BETTER THEN MY LAST SPEAKER, which was a 1000 watt 12 inch POS with a 1000 watt POS amp.. you need quality.. haha..
also, high watt amps cost a **** MORE to install.. you need special wire, and sometimes need to upgrade the alternator..
FOR SUBS, i would ONLY WORK WITH ALPINE TYPE R SUBS, or HIGHER grade.. i have NEVER HAD a better sub. kicker is also a great sub. but nothing else besides a few expensive ones are worth its weight in scrap metal.
http://318ti.org/forum/showthread.ph...589#post235589 
I think the lil e'ffer disconnected while pressing the unit in. DANGIT! 
Linear Mode
