New stereo

Hello again,
I just bought a full system, minus the subs due to weight, for my 1994 GSR sedan. I got a Clarion DRX9575rz HU, Polk/Momo 6.5 components for the front doors, Infinity Kappa 693.5i 6X9s for the rear fill, and a Fosgate 300X 4 channel amp. Problem is, I'm starting to worry about clearrance/size issues. I have heard that the door speakers are 5.25 but others say 6.5. Then the rear, I want to retain my factory grills but I have read that the top mount depth defeats this wishful thinking. Any ideas? Also, how do you think this will all sound?