New to DT virtualization

Many thanks for your time in advance...

Although I have been in IT for over 10 years now and have deployed many blade centers for server virtualization, I am clueless where to begin in virtualizing desktops.

I currently have a client looking to virtualize about 20 desktops. They have a blade center (Hyper-V) that currently hosts 8 of their servers (Server 2008 R2) with additional room for needed blades and hard drives. The thin client must support dual monitors. DT OS will be Windos 7

I guess I have the following questions:

1) What WYSE thin clients will I need that will support dual monitors?
2) What virtualization software will be best. Hyper-V or VMWare?
3) Do ALL WYSE thin clients support Hyper-V and VMWare?

Cheers!