Surfsasser

If I am trying to build SB players for the SB master sets, which event is better to spend stamina on?   i know the OOP events guarantees players to use but I have not received anyone who is 86+. Sometimes when I do banner events and exchange set, I get 86+ players. I don’t need anymore banners for the master sets so I would use all of those towards the trade in for players. Thoughts?