Does the car have no motor in it now and had a small block or does it have a smaller v-8 like a 318?
If you are trying to watch cost, another thing to consider is things like accesories, alt., water pump, power steering if you have it.
If you have these things, you open more cost saving avenues to consider.
For the motor that it sounds like you would like to have, you will need to buy new things like carb, intake, cam, headers and that does not include the basics like hoses, plugs, wires, oil and filters - this stuff really starts to add up in cost.
So if you are buying a "short block" and you have nothing to add to it used, it's going to cost a pretty penny to get it running.
If you buy a running motor, you can strip it, clean and save most items, and stretch where you have to and dirrect cash towards hop up items.
To be honest, and again it's just my 2 cents, I would find a running 360 - if and when you strip it a camera, zip lock bags and a note book are going to save a lot of hassle during reassembly. Find a shop to hot tank, bore, possibly deck head surface(what ever the block would need), install new cam bearings and clean the heads and possible valve job.
This will insure a solid foundation, and then you can paint easily to your liking, and my favorite part add your new hop up parts. You will also probably need a new oil pan for an e-body. Then add the rest of you old accesories and get ready to fire it up.
If you need to go even cheaper, you could even take the running motor and if it's not blowing or burning any oil and has good oil pressure you could just clean it and add your speed parts.