10-bit DAC video cards

1
I'm interested in doing some studies using finer grayscale luminosity
control than I can get from an 8-bit DAC. I've been reading about
video cards with 10-bit RAMDACs, notably made by ATI. Also, I'm using
a PC. So, two questions:

1) Has anyone bought a 10-bit DAC graphics card in recent years, and
can advise on the purchase?

2) How is the interface with psychtoolbox performed? Is it as simple
as choosing a 256 CLUT from the 1024 available from the DAC, or is
there other software involved?

Thanks, any insight would be appreciated greatly. And, I apologize if
this is a question previously addressed.