Based purely on weight and size advantage, I'd go with Gamboa. I don't think it's fair to mention Donaire alongside featherweights just yet.
Donaire does have the frame to eventally get up as high as FW , but thats really as high as i see him going , Gamboa will eventually jump to SFW in chasing Juanma as he has stated his future lies @SFW , and once he's there he will probably settle there as he's in his 30's now . So im not sure we will ever see Gamboa Donaire , that said Arum knows this , and he has control of all concerned , so you may just see Donaire fast tracked to the realms of SBW and FW if thats his aspirations ............... Gamboa TKO for me
Gamboa by KO. Too big, too strong. Donaire is better pfp, but that's a big leap up in weight for Donaire, and he'd be facing a major talent in Gamboa, not just any FW.
+1 This becomes a legitimate discussion topic for me if/when Donaire proves himself against the top guys at 122. Until then, I would favor the bigger Gamboa without giving it much thought.
Donaire. He has knock out power and Gamboa is quite chinny. 3 years from now this could be p4p 1 and 2