hi there,
the permedia 2 chipset sure does get really hot and eventually dies.
Have in mind that all permedia 2 chipset vga AGP and PCI cards made for the pcs,have a passive heatsink.I had to put a fan on to gain stability.
I also have a CyberVision PPC .Luckily ,the Cybervision PPC has 4 holes round the chipset for easy mecahnical support for the heatsink.Remember you need one with a fan.
On the bvision side,i sse the gap .
My personal advice is to avoid thermal paste/glue so to avoid any detach and burn the chipset.plase the heatsink/fan ,and use a plastic wrap belt to hold it in place.either bypass it at the hole in the middle,or from side to side.
take care,you have a history ultra tech amiga RTG.