If it was me, I'd source a block and buy a kit.
When you consider that you are buying an engine that got built assembly line style, only with some guy(s) knocking in pistons with no regard for much more than how many more they gotta do, I doubt that the quality of the build is ever that high.
Seems to me if you can find some bodies bare block, or donor engine for cheap as a foundation, the machine bill won't be any more than you want it to be..
"Square decking? Align honed? Balanced? Blueprinted? How would you ever know any of that crap was ever done if you didn't either pay a guy to do it directly, or do it yourself? ( the only thing you could do yourself is the blueprint part, and I seriously doubt any of those mid line engine builders do any of it.)
The piston gets an ots .030 ring set that isn't checked, the rods get a .010 bearing set that isn't checked, and the mains get a .010 set that gets equally thrown in.