The FE engines - 390, 427, & 428 (a few other, but are scarce) were built in the 50's and 60's with 390 continuing into trucks through the 70's. They are heavy iron engines. There were about 4 versions of heads with different heights. The 427 & 428 are the engines that originally came in the Cobra. Stroker combinations are commonly up to 482 cid and bigger can be done. They are capable of great power, but they are a complicated design. They are costly to build (50% more), and prone to quite a few problems.
Oil leaks being one of them.
The 385 series big blocks are 429 & 460 and can be stroked to well over 500 cid. This engine easy to make huge power at low costs. They are huge physical size. They can be put into a Cobra and are, but it is a very tight fit.
Ford made a 351 Cleveland. The 4V was the beast in its day. They were not made very long and are hard to find. Not as many after market parts available. People still use them in Cobra builds.
The 351 Windsor based engine can be stroke to ~ 408 cid and if you go with an after market block with a 4.125 in bore, it can be built with 427 cid. If you bore that block to the max you can get to 460 cid. By the time you get this built with the hug cid your into the FE price range. Stay at 392 cid and the price can be amazingly low.
The 5.0 ltr popular in the mustangs 80's up until 95 can be stroked to 331 & 347 cid. It is the least expensive to build. It is extremely light weighing at 400 lb in all cast iron from the factory. It is about half the weight of the big blocks. The block is the weakest and has been known to split, when pushed over ~500 hp give or take. The engine is quite tiny in physical size.
Any of these engines can be built many ways. There are a dozen or more aluminum heads made for most of these engines. Same with intake manifolds. Lots of stroker combinations available. You can use a factory block or an after market block (aluminum or cast iron). Aluminum is about double the price of cast iron.
Aluminum is light and easy to machine. It conducts heat very well. It has 4 times the thermal expansion as cast iron. It slowly creeps over time. There are many hardening techniques to overcome its stability problems. It requires much more skill to make quality parts from aluminum. The physically bigger the engine the more problems with thermal expansion issues.
In normally aspirated engines with good flowing heads about 1.25 to 1.3 lb-ft of torque per cubic inch is about the upper limit with 2 valves per cylinder for a street engine. The cam design will dictate where in the rpm range the torque will be made.
This is a very rough guide and the combinations of parts is just about endless. It is impossible to give you an exact answer. You need to be thinking about reliability. How much under the hood work you are willing and able to do? How big of a cam will you be happy to drive?