Everything to do with the ICE is tricky so any dosemu pain will just be a part of a more comprehensive painmaking operation. However, it does sound as if it may be a route with a chance of success.
I've seen a few motherboards and they are not crazily priced and I don't mind spending a bit of cash for the right thing anyway. Someone mentioned a PCI to ISA converter which may allow me to use my existing hardware but it does add another layer of abstraction onto the layers already introduced by linux and dosemu.