First, I love the idea!  Driving around Vegas in Katz's 65 Riv made a believer out of me.  It has "cool" written all over it.  
Enough of the "styling" questions, let's talk mods:  Are you gonna stick with the stock frame?  Stock suspension?  Got any weight reduction in mind?  Stay with the nailhead?  Manual or automatic? (uh, never mind).  
 
jp