[SummerSahar]

I know it sucks, but you really shouldn't order something like a brand new foundation color online. It's pretty crucial to go to a store to try a few on and/or get advice from one of their makeup artists. Once you've got your color, you can keep ordering it online, but the initial color choosing should be done in person. Especially with MAC! There are so many!
Does the online store have a good return policy? At least that way, if you get the wrong color, you could call up a makeup artist and tell them "this color was too pink on me. Do you have something in the same shade but minus the pink a couple of notches?" They can help you try again.

Other than that, I can't offer comparison advice since I've never used Ben Nye. I use a liquid foundation from the drug store and then I use bare minerals powder foundation on top. All the MAC foundations (and bobbi brown's, too) always looked so cakey on me and made me look super old. Anything that thick looks odd on my face. The liquid plus minerals looked the most natural on me.