I've been pretty quiet on this thread, mostly because much of what I'd add gets covered before I see things.
That said... I like to go through levels of invasiveness, and, through levels of necessity.
You have choice a) just get it running, reliably, and at the minimal cost. Here you do what I call spring cleaning, things guys have said - oil pump, check bearings, replace gaskets and seals, do your pumps, tstat, ignition parts, etc. Maybe you check the existing carb out, or get a perfect working and cheap 2bbl & intake combo someone pulled for a 4bbl. Beyond that... you save your bullets so to speak. You actually plan on future downtime for the car where you get into pistons, cams, shaving heads, port jobs, carb upgrades, so on so forth.
Then there's choice b) you plan what your garage/downtime situation is like, and, thinking about exactly what you need before you're happy with the car, you do stuff to avoid repeated efforts. Then, you do the most invasive stuff first, while the engine is out, and things are pulled apart. Heads you can change in the car later to add porting. Maybe you choose a big carb or a FI conversion down the road. That's all easy to lean over a fender and mess with. A cam you might as well do while everything is already apart, front cover is off, oil pump is getting redone, etc and it's already apart under this approach.
Time also impacts things. Looking for DEALS saves you money and gets you further. Getting it done NOW means paying higher prices for stuff. So you can stretch your budget based on how things work for you, and, your rush to get it together.