I like JBL speakers. They have their own sound if you like it.
Be sure to get an EQ with as many bands as possible so you can adjust it to your liking.
As far as amps, go listen to some installations with a CD that you own and know what is should sound like. Take the CD to a stereo store and play it on a high end system so you have something to compare it to.
You won't need 1000 watts or anything close to that. Look for the RMS ratings. 100 watts RMS amp for the bass (a bigger speaker size 12"-15"is usually better if you have the room), 25 watts RMS each for mids/tweeters will be fine for clarity and great sound. 4 speakers (two front tweeters and two rear (mids/tweeters) with one sub should do you fine. If you want to double those ratings that's fine too. Be sure to get speakers/cross overs that can handle the RMS ratings.
2004 E60 530is, Delivered 12/12/03, TiSilver/LGrey, PP, SP,PS, PDC, ACC, FRS, Step, Xenons, clear bra, body colored rear inserts. (Retired, 1983 henna red 320is)
2004 Corvette Z06 Commemorative Edition