Well you are asking a big question. Lets start with the Amp question. It all depends on you budget to start off with. Next is what are you going for, just ass pounding bass, or do you want an amp that can be used for all the items in your car and good sound quality?
But to get to what I think you are asking, you will need to get a good quality amp (not one from Wal-mart). There are a bunch of good amp manufactures out there and there price varies. But I like Concept, Orion, phosgate. Concept is the cheaper of the three, and if you do into the D-series they are stable to 1 Ohm.
Also when thinking about an amp you will need to know how you are going to wire the subs. Mono, or not. I would run your speakers in parallel and drop them to 2 Ohms, and get a mono block amp. Most amps come with a HPF/LPF (high pass filter and low pass filter) which will allow you to take the highs or lows out of what ever speaker you are powering.
As for the power for the speakers it depends on what type. If you are buying some Pyramid and they say 1,000 Watts, I would not get anyting bigger than a 100 watt amp. A lot of companies over-rate there speakers. But if you are getting a good quality speaker the RMS of the amp and speaker should be close. If you have a 1,000 watt good speaker you can run it 500 to 800 watts and it will sound great (depends on the enclosure too) Different enclosures sound better at different power ranges.
As for the wires that again is hard to answer only because it depends on the size of the amp, and the current draw of that amp. They sell kits based on your amp size that comes with power, ground, RCA'S, Fuse Blocks, and so on. But if you are looking at anyting from 500 to 1,000 I always go with a 4 ga power wire to a power block (this allows me to do expansion later if needed). That way you have the option of going up and down in wire size off the block. I would hate to tell you to install a 8 Ga power wire, and then later on you want to add an amp, and you have to re-wire it all again. Start off like you will expand, (because trust me your system will never be good enough). You will always want MORE. It may cost a few extra dollars now, but it will save you in the long run. My advice is to look around your area and write down the different brands of amps and subs you have there. Post a message and ask for information on the items you are interested in. YOU PAY FOR WHAT YOU GET is so true in car audio.
