British-Pakistani boxer Amir Khan claims he is ready for all comers and challenged some of the top fighters in his division to a showdown this May.In a tweet, Khan challenged Floyd Mayweather, Manny Pacquiao, Miguel Cotto, Timothy Bradley, and Juan Manuel Marquez.Mayweather, Pacquiao, Cotto, Bradley, Marquez all available to fight around May, Khan tweeted. Im ready and want to fight the best.He also added the hashtag Lets Make It Happen.Khan has been publicly campaigning for a fight against Mayweather for a long time now, and has also expressed willingness to take on Pacquiao, his former sparring partner and stablemate.It is possible, however, that Khan may be left in a lurch as Mayweather and Pacquiaos camps are currently negotiating for a May 2 super-fight.Thus, the former world champion called out other top fighters, including Cotto, who currently fights at middleweight.Khan told his Twitter followers that he would fight Cotto in a heartbeat in a bout that can be held at catchweight of 155-pounds.Stylistically, Cotto would be a great fight for me, he also said. Hes a great champion. Just imagine that fight in the UK. Click here to read full news..