Just something to consider:
If the piston to bore wear is within reason, why not do an economical refreshing of this engine?
By that, I mean to replace the rings, bearings, timing set, cam and lifters (if what's in it is too worn or is a complete unknown, or not suited for whatever reason for reuse), gaskets, an oil pump and a valve job. That way, you have gotten the whole experience of what the dis- and re-assembly entails, and a decent 40K- 80K mile engine out of the deal, as well.
Machine shop work will be limited to cleaning the castings (if needed), honing the cylinders, the valve job and polishing the crank. You should be able to bring the whole thing in under $500.