Hi. More info might help. What car & year, what do you want at the end of it - an MOT pass for this year or a long term fix?
Depending what your end goal is, I have been looking at doing something similar on my 90s Renault (I ordered new piston rings before I realised the bores were worn - I fitted then new rings, not sure yet if they have helped enough)
For testing around the yard it now has an open vented breather. If that works I'm considering venting the breather into the large airbox in an attempt to re-burn the oil mist ... I suppose the next level would be a catch tank setup draining back into the sump and venting air from that into the airbox...
For my 70s Hillman new pistons & rings worked wonders to bring it back into spec even with slightly worn bores..
A known good engine is often the most cost effective solution if you can find one. Good luck, keep us updated