After considering the scroll compressor performance issue I was unaware of, I'm more tempted to go with a traditional R4 (but new, from AC Delco for the 2 yr warranty), or go ahead with the Sanden conversion. I personally believe it *should* fit with those same simple adapter brackets, but in the event it doesn't, I'll be the one stuck with restocking and shipping fees...so unless I can get one of the suppliers to confirm it'll work, it may be a no-go.
EDIT ... after a bunch of looking it seems like the Sanden conversion brackets only work with the aluminum accessory drive bracket. Mine is a combination of steel with a few cast iron pieces.. bleh. I think I need to keep this simple and stick with the R4 compressor.
Richard