Well, the standard 140mm probably won't work unless you had bigger clips.
With that though, buying 2 140mm fans + the FUMA doesn't really make sense. Here's why:
1) The FUMA is attractive because of a) low price and b) low height
2) Buying 2 140mm fans make it cost as much or more as a bigger cooler like the NH-D15
3) Adding 140mm fans increase the height of the FUMA to that of the NH-D15
So, the conclusion is if you want to use 140mm fans just buy the NH-D15. It's a better cooler.