So these are the speakers im going for
polk momo mmc460 for front
polk momo mmc690 for rear
2x polk momo mm2124dvc subs
polk momo c400 amp

SO questions are, would I be better off fabbing custom brackets for a 6x5 front speakers.

Can I use my stock wiring, or should I run all new wires.
What else am i missing for this setup to work?
Is this plug and play?/ Thansk!!!

The Polk Momo Line is an AMAZEING line up. I would go with the MMC6500 components up front. I had them running off a 300/2 and it was amazeing. But what amp are you gonna run the subs off of. I would recomend two 500/1. Well just let me know. Also your gonna have to run all new wiring. 16 guage min wire to all the speakers and 12 guage to the subs.