I’d use M1 5W-50/15W-50 without hesitation for “easy to get” oil. M1 5W-50 carries Ford GT40, Nissan GT-R, Lexus LFA and probably Porsche approvals. If Ferrari OKs 5W-40 for a vintage Testarossa, PP Euro 5W-40 with the Ferrari endorsement could work.
Else, Red Line 5W-50/15W-50/10W-60/20W-50. You get the best of both worlds - lots of ZDDP and an POE/PAO base.
Else, Red Line 5W-50/15W-50/10W-60/20W-50. You get the best of both worlds - lots of ZDDP and an POE/PAO base.