A/C compressor for 77 Cordoba

We just replaced the A/C compressor on my 1977 Cordoba it worked fine but now it has got an oil leak. Local parts houses don't have any replacements. What's a good source for a reman? I see them on eBay and also Rock Auto but am a bit concerned about those sources. Any recommendations? TIA

Rock Auto has my trust and vote

Classic Auto Air in Florida, they rebuild RV2 compressors.

I went with RockAuto and got it all installed today. Working fine, quiet, cold so far so good. I did take a look at the other vendor recommended and they look good. It appears they rebuild compressors as well. I have noticed there are two kinds of compressors. A V twin that looks like a Harley Davidson engine and a single piston type. The parts guy at our dealership said the first was factory air and the second was used in dealer installation set ups. Is one better than the other? How hard would it be to swap them out?