Who are some free agents we've seen fight in ufc, bellator, strike force, etc. That you'd like to see fight in One Fc? I think thiago silva (crazy cooked up SOB but damn is he fun to watch fight), Melvin Guillard (not technically free yet but is on super thin ice with wsof) and Sergei Kharitoniv could all be very fun ones to see. 
Cody mackenzie, cro cop, and JZ cavalcante would be fun too.
Alessio Sakara
Something about cyborg soccer kicking someone in the face, even if it's only for one fight excites me, lol 