Make the fight. Khan vs Bradley for the WBA and WBO is big business. A real unification fight should pack out a good venue. The O2 would be a good idea. I think they can fit 20-25,000 in there. Bradley is the man at 140. Remember, he had the WBC title. I'll tell you who has a serious record at 140 but has been forgotten - HOLT!
The risk/reward factor is not great though, is it? Holt strikes me as one of these hot-and-cold fighters. If he comes in hot he would probably have too much for Khan. If he had have applied himself more in the contest he would have defeated Bradley. He just seemed content to take too many rounds off, letting Bradley pick up the points without too much effort.
WAY too dangerous for Khan. He is in a tough situation. You are right. If he is on, he seems to be able to perform real well. I read an interview where he said his right hand was mashed up and he has also had elbow trouble. He has fought so many good fighters though - undefeated Diz, undefeated Hopkins, champ in Torres, champ in Bradley etc etc