'96 Yukon 2-dr. door speaker upgrade q's

I just bought a set of Polf mmc6500 components, and I have a few questions before I jump in. The speakers came with crossovers, and I dont know where to mount them, any suggestions? I'm planning to amp the speakers and I am thinking about replacing the factory speaker wire. Will it make much of a difference or should I just leave it? Also I'm not sure where I'm going to mount my amp. Any suggestions would be appreciated. Oh ya I am going to put a sub in pretty soon also so give me any suggestions you have for stealth install. My goal is to get nice clean, accurate sound over a large range. I'm not interested in rattling the doors off with bass, but I do like to hear those lows hit. Thanks--

Run new speaker wires. Mount the crossovers inside the vehicle, not inside the door where moisture will detroy them. Top Secret, I can tell you but then my wife will kill me.