Question about Auction Software and User Profile Software

Hi,

I'm interested in starting my own internet auction business. Does anyone know the name of a good auction software and where I could find it? I'm not interested in running auctions through eBay.

I'm also having trouble finding software that will create user profiles for another site I'm interested in creating.

Any guidance would be appreciated. I know there are a lot of different opinons.

Thanks,

Dan