I don't know if you already found a replacement radiator but if you haven't you may be able to fix your trashed one. Check out http://www.motorcycleradiators.com/ This guy literally fixed one of my trashed radiators for 55 bucks. He has a fast turn around and does great work. I don't care how mangled your radiator is he can fix it and fix it right!. I couldn't even tell mine had any damage.
Regarding radiator guards, when I munched my rad I had Devol's on. Since then I have replaced them with Flatland Racing Rad Guards and in my opinion are much stronger.