Fastest pc motherboard with isa slots?

[Piru]

I have an I believe a 600mhz motherboard/processor but I was wondering whats the fasest cpu/motherboard around with at least 2 or 3 isa slots

LGA775 mobos with ISA slots exist that'll handle at least FSB 1066 C2Q CPUs.
For example http://www.adek.com/ATX-motherboards.html

New mobos are still manufactured with ISA slots, mainly due to them being required in the special controller PCs. Many factories still rely on custom ISA controller boards that have no PCI/PCI-E replacement.

EDIT: Some of the newer mobos don't do ISA DMA however, as ponted out.

[Piru]

As I said and the page clearly states, it does not support ISA DMA.

Oh indeed, that can be a problem of course. I think the last industrial PCs I saw were c2d however, so I suppose those particular controller cards didn't require DMA.