Sanity check re engine swap options/planning

I don't think that swapping any modern V8 will come anywheres close to your projected budget. For the kind of money you are looking at you should be thinking about finding a good used engine and transmission to drop in. You will still need V8 radiator, battery?, etc. Factory front disc brakes are a relatively inexpensive upgrade. Good to think about these things ahead of time so you end up with a fun car.