You want to do TBI if you can. It's as easy as dropping in a carbed engine and you get FI. Go advanced adapters for the pieces you need. I've done this a bunch on Toyotas and it's very, very easy.
AdvanceAdapters.com | Engine & Transmission Conversion Adapters - Advance Adapters
Get the motor mounts and stuff from them, they also have some conversion guides. On a 50's pickup you can do this in a weekend if you handy with a welder.
Oh and you don't need any wiring with the TBI engines, you keep the computer from the donor vehicle it's all one harness. After that you have four connections to deal with that are all either switched or not for 12v. Everything on the TBI engine is encapsulated, nothing is external except for the fuel pump, and that's an off the shelf item.