I have a 73 Delta 88 Royale 2dr hardtop and I am in need of new rear quarter panels both driver and passenger side. Is there anywhere that sells these, also I am in need of new fender trim pieces, like the fake vent trim pieces that are on the front driver and passenger fender.

 

I don't think there are any vendors who reproduce sheet metal for the B/C cars. Your best bet would be to check with any of the guys who are parting cars. A few names come to mind:
2blu442 - John McNeel - Medford OR
Oldspackrat - Scott Winn - Indianapolis IN
jensenracing77 - Eric Jensen - Brazil Indiana
507OLDS - Brian Trick - PA

Also, I'd suggest you have this post moved to the 'Parts wanted' section of the site. Likely you'll get better results.