The 6.2 is a damn good board. You probably wont find a better one to build, as 6.3/6.5 is pretty rare.
When trying to "max out" an A2000, remember this: The expansion bus is only 16bit..
So get everything you can on the accelerator.. Anything on the accelerator is hooked to the CPU via a 32bit bus and will perform a whole lot better than anything you stick in a zorro II expansion slot. Stuff like sound cards, serial ports, etc. are fine as 16bit cards.. Stuff like memory, hardisc controllers, graphics cards, etc. are best on a 32-bit bus. So the key to having an A2000 with decent performance is DON'T SKIMP ON THE ACCELERATOR. You should definitely try to get one with a decent amount of on-board 32-bit fastram and on-board scsi at the very least.
The abslolute baddest accelerator Ive ever seen for the A2000 was the DKB Wildfire 060/50mhz. It was roughly comparable the Cyberstorm/Blizzard 060 cards available for the 32-bit AMIGAs.
Wildfires are probably pretty damn rare nowadayze.. but if you really want to make your A2000 compete with the A3000/A4000/A1200/T systems, it's the best option. And, I believe it even had on-board ethernet.
