Bayern won´t let Hargreaves to ManUtd, at least not for 2 more years, Schweini would be a fantastic direct replacement for Nedved, but it seems Juve is not interested in him and probably Bayern wouldn´t let him go since we don´t have good relations with Beckenbauer
I would go for Mascherano, we need him the most out of all interested clubs and he isn´t appreciated in West Ham. On the other hand, Deschamps is a big fan of Mascherano and he would be guaranteed first team football.
I must add that 18 million Euros is not too much for him, I just hope West ham won´t ask more money for him, cause then it is not worth it.