Right side steering - To be honest it would be a fun novelty . I drove street sweepers for years which are ,of course, right steer , you get used to it very quickly . Think of all the inquiries you'll get a shows ...and all the ******** lines you can make up
Copper would be the best metal but you're going to poop your pants when you see what that size copper tubing costs these days . Blame the Chineses for outrageous metal prices
You didn't note what kind of horseponies that you're going to put in front but many of the older import trucks have pretty beefy and narrow rear ends . I have a Nissan under my roadster , it is perfect .
I have a VW bus like donsrod suggested . The car isn't finished yet so I haven't driven it but several friends have used and loved them . They are fairly easy to come by . Also by using a typical punch chisel you can heat the end and drive the chisel in and it matches the taper for most rod ends
I used to drive street sweepers with no rear suspension . DO NOT DO THAT !!! You will REALLY regret it . And it can do weird things to the handling too . Trust me on this
When I was a teen in the 60's and living in Lancaster , Ca in the high desert we had a trailer at the River for water skiing . There was a gas station out in the middle of nowhere that we would stop at occasionally that had the glass pumps . My dad would let me do the pumping . Too fun !!