crossovers

Man I've got lots of questions. Ok, I heard that I will need a lowpass crossover for my sub to make it sound better and to lengthen the speakers life. Will I need another crossover for my cabin speakers? If so, what are some good lowpass and highpass crossovers under $200? And what's recommended active or passive?

Also, I've got a 1 ft3 sealed box for my sub and I plan on paralleling my wiring, Will my amp be able to take this much power since it'll be going from 2 to 1ohm?

And another thing, I'll be getting my system installed professionally but, what the heck would i use to connect the terminals on my sub. Should I just stick the wire in the hole? (Just for future reference.)

Here is my Configuration:
1 12" kicker compvr 2ohm
1 jbl bp 600.1
6 1/2 pioneer 3-way
6 x 9 pioneer 2-way

[ebpda9]

i don't think you need a crossover for the cabin speakers. You want them full range

Would you know of any good crossovers for my sub then?