managing membership

I am running a project of an e-commerce website. The project got a problem in a membership. I have tried many plugins on a membership, and now I am using S2member for my member system. However, I am still looking for another function that is not supported in S2memeber.

I’d like to create two kinds of main members in the website. One is a customer and another one is a seller. And each kind of member has different levels depends on their sell.

I struggled on the two kinds of membership. Could it be possible to just use two different member system or two different plugins? But it seems like all membership will save member information in the same path or the same form.
Is there any member system or solution that is match with these goals?

Any suggestion and help you can give will be greatly appreciated.