I wish i could do this!! But the sound track is funny, for about the first 45 seconds RedTube - Deepthroat Compilation
Tons of guys here would let you practice on them. Hell, if I was your bf I would let you practice on them!
I can do that and then some...besides most of those cocks are not big enough to even warrant a blowjob from me. I set a standard of 10 inches or more. anything less I would walk away from. Once you go big you dont go back to anything less..better to have nothing than something small in your mouth..
another deep throat vid for comparison......It's guy on guy and he's really good: http://www.lpsg.org/sex-with-a-large-penis/56059-proper-deep-throat-technique.html