Yes. Per the specs as listed on Newegg.ca as well as it's own spec sheet on the ASUS web site, The ASUS M5A99X EVO R2.0 motherboard does support SLI. It has 8 USB 2.0 headers and 2 USB 3.0 headers. It also supports the AMD FX-8350 processor though a BIOS update (1006) is probably required.
Yes. As long as the links I provided are to the correct components, I'm sure.
Newegg Link in the overview:
Quad-GPU SLI and Quad-GPU CrossFireX Support!
Flexible Multi-GPU Solutions, Your Weapon of Choice!
M5A99X EVO R2.0 brings you the multi-GPU choice of either SLI™ or CrossFireX. The motherboard features the most powerful AMD® 990X / SB950 platform to optimize PCIe allocation in multiple GPU configurations. Expect a brand-new gaming style you've never experienced before!
Newegg link in the Specifications:
USB 1.1/2.0 8 x USB 2.0
USB 3.0 2 x USB 3.0
ASUS CPU Support List:
FX-8350(FD8350FRW8KHK,4.0GHz,8C,125W,rev.C0,AM3+) ALL 1006