I have enough miles on both 2v and 8v CARCs that some people here think I know what I'm talking about. (You know who you are, and I hope you're right!).
CARCs can work with lots of things, but they work best when given 10W60 of the appropriate spec level. The least expensive source that is actually reliable is NAPA, where Liqui-Moly 10W60 (automotive specification, but it meets all MG requirements) is available in 5 liter jugs for a reasonable price.
Filters you can get from WIX all day long, as well as from other good sources, but the Mobil1 102 (now listed as a 102A, mostly a marketing upgrade) is a great filter that is available inexpensively throughout the country.
Personally, I would not run anything other than 10W60 oil. But what do I know, with only 250,000+ miles on CARC bikes?