Matt,
Like Jock said build it the way you want, but I can offer my experience.
I refurbished a '53 2 ton dump for my roofing business.
It looks & works great, but doesn't compare to a modern vehicle for ease of use, consequently, I find I don't use it as much as expected.
It only goes about 45 mph, is slow on the takeoff even from 2nd, & is hot in the summer without a/c (granted I live in Florida).
If I have alot of errands, & distance to cover I'll use my '99 pickup instead.
SO, I would modify the truck with a modern driveline & suspension. & add a/c.
The only possible exception being the straight front axle. it could be done later if desired.
Since this will be used to haul your racer, dependability is tops on the list. I would think comfort & ease of use would be too.
All you want is a cool looking hauler for it, your attention will be focused on the rail, so you want a reliable turn key operation to get it from point A to point B, right ?
Rick.
my truck;
http://www.stovebolt.com/gallery/schultz_rick_1953.html