, and here
are some good info. Looks like they're just souped up versions of other cards (the GTX465 in the Q5000's case). I remember that, that FireGL and Quadro are the same as other cards often with just different device IDs and drivers so they work with pro software.
The one mentioned in that thread may have been a non-reference design (PNY) so that could be why it needed a universal GPU block and ram sinks. If the 5000/6000 series follow a reference design, then you can likely use a full-cover block designed for the non-pro version of the card that it comes from