While crossovers may not be canon, Darkseid vs Galactus was the only book in which Surfer and Orion have ever interacted. Since it is the only depiction, it may not be gospel truth, but still carries significant weight in influencing my opinion.
Aside from that, I see Orion having several weaknesses for Surfer to exploit, including his flying harness. It doesn't seem as though it should be difficult for the Surfer to manipulate it off of Orion, which will remove a significant portion of Orion's combat speed and manueverability.
Also, there is no proof to back up the assumption that the Astro Force is greater than the Power Cosmic. That being the case, the character with more experience controlling their power is the one who would probably prevail in this category. I'm willing to bet Surfer has more experience here.
I see Surfer winning this battle 7/10. This becomes 8-9/10 if he can consistantly disengage Orion's harness.
I would have to go with Silver Surfer
SS can match Orion in any category and can do much more.
-Speed 100X light speed feats
-Stopping time instantly
-Force bubble to trap Orion’s equipment
as for durabilty am sure SS can take most of Orions blast with ease.
and ya if he does get hurt he can always heal
7-8 - SS wins