USB 3 / SATA 6gbps on LGA 1156

I'm starting to put together plans for purchasing a new system, and at the moment I'm debating between 1366 and 1156.

On the 1156, is it true that 1) Using USB 3 / SATA 6gbps will put all PCIE slots at 8x? and 2) that you cannot use both USB 3 and SATA 6gbps at the same time?

I need to be able to use them both simultaneously and while I do not intend to SLI/Crossfire, I don't really want my single GPU to run at 8x.

Could someone please clarify?

Thanks.

EDIT: perhaps I should add that when referring to USB 3 and SATA 6gbps I am talking about the controllers that come with the mobo, not the add in cards.