In my A4000 with mediator I use Voodoo3 3000. It's the best in my oppionion. Have a Voodoo3 2000 and Voodoo5 5500 but the 2000 is of cause weaker and the Amiga becomes the bottleneck and can only use 1 GPU so the 5500 power goes to waste... also it's way big, requier extra power and gets hotter. But they are good for backups.
Attaching a heatsing to the 040 isn't that hard. If you can find a dead 3640 board they have holder for heatsing, else use heatcompound and clean of the corners of the CPU and add heat tollerant glue there.
