slash... best motor?

[rcsammy]

hello everyone, i got a traxxas slash a few days ago
i already have a MM and im soon to be geting a 3s lipo
so looking for suggestions on which motor to go for? dont realy have a budget at the moment as i will just see what there is
the only two motors i realy know of are the mamba 5700 which i have heard good things about and it is also waterproof which is a big plus as the rest of the slash is
and then the velineon which seems to be the preferred motor on the traxxas forums(i wonder why)
thanks, sam