Where to start on my project (1972 Gmc Jimmy)

[Sandtrap9072]

So i am now settled into owning my first home and i am looking to start working in my garage. I have a few things that i would like to do to my 72 gmc jimmy but what do i do first? I need your input. The truck has a bbc in it that i would like to replace with a sbc. Reason being, is that i want to put what came in the truck back in it. The conversion to the bbc done by the previous owner in my opinion was done quite half ass. But, If i decide to go that route, what do i replace the bbc with without out spending a ton of money. Do i replace it with a motor from a donor truck and have it over hauled or buy a brand new crate motor with a warranty. If i decide to buy the crate motor, how do i know what brackets i need to put the sbc back into the truck? The motor is just one of the things on the list. I could also go through the suspension and other drivetrain components. ie Replace the hubs, wheel bearings, pieced together lift what all new parts. I guess i just need some input on where to start. Any input would be greatly appreciated.