If I recall correctly, the only difference between those 2 is the cooling. And the cooling wont be ur problem if ur not planning to overclock them. So there is really no difference. I trust more in EVGA then MSI tho :=)
Yea if Im buying nvidia I got with evga, use to rock xfx but gone off them due to mobo issues which I know is nothing to do with gpus but put me off the whole brand. For the most part there is no real difference, some reportedly offer varying degrees of customer support so that might be a consideration. Also some offer non reference coolers which is usually my biggest factor on what mfg to go with these days.
My very general rule of thumb is:
Nvidia = evga
ATI = Saphire
or if they are doing a particularly cool card from either = ASUS