I have a Nissan 350Z...I'm replacing the stock door speakers/tweeters and rear speakers. I've decided on the Infinity 6010CS components *90W RMS* for the front

(http://www.circuitcity.com/ssm/Infin...oductDetail.do)

and Infinity 6012i *60W RMS* for the rears.

(http://www.circuitcity.com/ssm/Infin...oductDetail.do)

I want to power the front components with an amp and possibly add a sub at a later time also powered by the amp. Here's my questions...

1) Can someone lead me in the right direction on choosing an amp with enough RMS power to use for the front speakers? Would this work?...

http://www.millionbuy.com/prfap600.html

2) If I plan on adding a sub at a later time, should I go with a 4 channel rather than a 2 channel amp?

3) When connecting the speaker wire from the amp to the speakers, I understand it is possible to run the wire all the way to the speakers or just tap into the appropriate speaker wires in the harness. It's obvious the second choice is easier, but which is best? If I tap into the harness, am I using a T-connector or am I supposed to cut the wire in the harness? Explain the appropriate way to connect the speaker wire from the amp to the speaker!!!???

Thank you!