IMO, Syn + 3Mo/3k = waste. For that OCI you could run any name brand oil with no worries. Valv Conv is good oil, and I had a good UOA at 4k and 5k minumum was recommended.
You can run search under my screen name and find it.
That said, I'd go with the best value name brand oil I could find right now. That would include Quaker State, Pennzoil, Mobil Clean 5000, Motorcraft if your running 5w20. Valvoline in jugs is a little higher than those at this time. I'm using Wally World jugs prices as reference.
Heck, you could even run Super Tech or one the parts store brands with an oil change specials with that OCI. See O'Reilly Oil oil change special.
And, maybe after you're here a while you'll feel more confident running a longer OCI.
HTH
J