scotty v

I gutted my old grand prix and am installing all of the stereo equip. in my 1st gen cl. i have an alpine 1.5 din - where can i find a bracket to install this h.u. in the double din slot? also, will i need to rewire each speaker, or can i use the existing wires to run to an excelon amp? as u can tell, i'm not very knowledgeable w/ car stereo stuff, so help me out. also - i was drawing a signal off of my rear speakers for my subs and excelon amp, but something shorted or something because the protection light came on it no longer works (it's still getting power though) - any ideas? this is why i am gutting the bose and doing it right - i have all of the equipment, so why not use it. will kappa 6x9's fit in the back?
thanks in advance for any help guys. sorry this is so long, but i'm kind of a dumbass with this stuff and have had bad experiences in the past with installs.