I'm not familiar with your specific vehicle so I can't comment on it directly. However, in regards to your question about speaker wire...it depends, but generally no.
If your factory system incorporates a factory amplifier and you end up pulling that amplifier, then yes, you will probably have to run all new speaker wire direct from the head unit or amplifiers to your speakers. While you could possibly install your aftermarket amplifier in the exact same location as the factory amplifier and thus pick up the wires there, it would seem to be too difficult and time consuming. Many times, factory amplifiers are MUCH smaller than aftermarket ones. Think in your head about the way that the factory speaker wire is run...from the amplifier to your speakers. Also, it's VERY thin gauge wire, designed to not carry much current...so if you're upgrading a decent amount, you really should consider upgrading your wiring to take full advantage of the money you've spent on new components. Speaker wire isn't all that expensive at the level you'll be playing at so just consider it part of the cost of the project.