It is very simple either we buy Falcao and make him
our main striker or we have to buy somebody new.
Wilson is not ready yet for atleast a year or two, Rooney is midfield under Van Gaal, Hernandez wont ever be a main striker at any top club and RVP is declining too much to be the main man.
I think Falcao can pull it off but only if he gets 100% support from the manager, he shouldnt be forced upon Van Gaal, Van Gaal needs to want to have him and he must play him as the main man which means if he is fit than he plays infront of anyone else . He has done it this season with RVP but 6 motn-hs later and he plays even poorer than under Moyes. In RVP's case it is a matter of age, real actual decline. In case of Falcao it is more a question of matchritme and a coach that isnt really giving you any chances.
If we'd go for somebody new it wouldnt be a bad idea to go for Lacazette.