I've had great luck with the following companies in my restoration (my car is pretty much brand new)...
-Roseville Moparts (Michigan): They have a ton of NOS and aftermarket parts.  I live right by there fortunately.  It's in the back part of a Dodge dealership, so they're always open!
-Mancini's (Michigan): I also live near this place as well.  They're helpful and have everything, but they're expensive.  
-Legendary (interior):I bought my seat covers and foam from them.  
-A Deals (Ebay): I bought most of my replacement (AMD) metal from these guys.  I think I purchased just about every available metal replacement parts for a 69 RR.  I also bought my carpet, gas tank and sending unit, windshield, and a ton of other stuff from these guys.  Call them, don't order online.  They're my favorite vendor.
-Inline Tube (Michigan):  I bought all new stainless pre-bent lines for my entire car (e-brake, brake, fuel) and also purchased their disc brake conversion for my front end.  
-My bumpers were restored by a company called Hajjar Plating (Michigan).
-I also used another company for items and I can't for the life of me remember what the name of the company is.  It was a two man operation in Minnesota I think.  They were recommended on here, so I'm sure someone will recommend them.
It was Mega Parts!  They are awesome.  I bought a ton of stuff from them.
Alex