Honestly, I would not do this trade if it involves Manningham. I don't think your as deep at WR as you think. Edwards is good (but too early to tell if he can be a monster in NY), and ochocinco is good, and bryant can be good again, but other than that, I don't like your receivers (not a fan of knox, garcon as u pointed out has limited time). Also, your RBs are not bad at all for a 14 team league. 3 legit starters in barber, slaton, and ricky, and choice is a good backup. I think Manningham is too good at this point to trade him away with edge and garcon only for Chester Taylor and and Hakeem Nicks (Manningham right now is a top 10 WR). If you're going to trade Manningham, I'd suggest going higher than Chester Taylor.
That being said, however, I have no issue with the trade if you replace manningham See if he will take TO or Antonio Bryant instead, since they are worth less.