Classic Surfer and Thor would be a well-argued match. Current Surfer, though? I think he'd take a few more out of the majority. Besides that, the Surfer is easily the fastest out of any here, and can multi task like a mother. Hell, he might be able to solo team two.
Errmmm...Thor has never shown the kinds of speed that the Surfer has(his best speed feats include moving "Almost faster than mortal eyes could follow" and swinging his hammer at multiples of lightspeed. Even compared to the Surfer's WORST speed feat, Thor is outclassed.), nor a mastery of multi tasking while using complex abilities....
Thor and SS could each hold each other off for a while, but I think FF take the avengers. If you gave the avengers prep w/o giving it to RR then it could be different.
Surfer solos. He will eventually beat Thor, who will be the only one left after Surfer blinks the rest of this weak Avengers lineup into nonexistence/another galaxy/hypno-sleep/whatever in the first split second of the fight.
I think the real trouble card in the line up is going to be Vision since he can go intangible and phase ppl into the ground or his hand into them and when he is phased I'm not sure Sue's FF will do anything to him.
Team two. Thor and Surfer is a push, and the Avengers would beat the rest of the FF. In a prepless environment, Pym owns the living hell out of Richards, and could likely down down a few of the F4 on his own. You also have Tony's firepower, Cap's leadership, and Vision and Wasp running interference.