First: stop being sorry for not knowing what you're doing! We're a pretty friendly group here, and are happy someone new is getting into the hobby.
Second: to get an idea of what you'll need for the front suspension, you'll need to get some reading material. Order catalogs from LMC, Brothers and CCP, and get familiar with what's out there in the way of conversion kits, parts availability, etc. And I always recommend having the catalogs versus on-line versions because you can take notes, read them in the bathroom, quickly compare things, etc.
Also, get a subscription to a truck magazine. Custom Classic Trucks does a pretty good job of covering early trucks.
Now, as for the conversion: I don't own the same body style truck you do, but they're pretty popular, so I would be very surprised if a V8 conversion kit (motor mounts, trans cross members and radiators) isn't readily available from a couple sources.
You'll do well to swap out the rear end for something later, and more common. Ford 9-inch, GM truck rear, Dana 44, etc. Your options here are wide open. As you get more familiar with the truck, this site and your research material, you'll be able to make a better decision. Swapping rear ends is pretty easy, and if you can't do it (because of welding on new spring perches), just about any shop can do it for you, and shouldn't be too hard on the wallet.
Engine: 2 years ago, I bought a $1,300 crate 350 from the GM parts counter. 290hp, 300lb. I'm VERY happy with it. I had a 4spd granny gear with 1:1 final drive and 3.55 gears, and it went down the highway in the left lane just fine. I've since swapped in a 4spd OD with .72:1 final, and rebuilt the Dana 44 with 3.42 gears, and it gets down the road VERY nicely. Mine is a manual trans, and I'll do some towing with it eventually. And auto trans will work very nicely with any GM crate engine.
Keep it simple with an Edelbrock intake, Carter 4bbl carb, and cast-iron exhaust manifolds.
You'll need to redo the entire wiring system anyway, so making the conversion to 12v will be pretty easy.
-Brad
