WIll a PCI-E 2x16 work on my board...

Helltech

Distinguished
PCI-e 2.0 has double the bandwith of PCI-e 1.0a and PCI-e 1.1. This is fine though as even if you have half the bandwith only the highest end cards will fully saturate that lane. Which means you will see little no difference in performance. They are the same slot physically when it comes to if the card will fit in it or not.