Well if you don't want to make your reasons public that's fine, it's your choice...but if you gave us a better description of what you want to do it would be easier to help you.
Not sure what you mean, "Run it under windows". Windows 98 is an overglorified DOS Shell...do you want Win98 to run as a Shell for DOS 6.22 instead of DOS 7.10? Do you want a DOS window in your Win98 that is DOS 6.22 instead of DOS 7.10, and do you want it to behave as DOS 6.22 used to (with 640k memory limits and crap like that)?
You might want to try posting this in the Operating System forums. It really has nothing to do with hardware, it won't get buried as fast, and people that visit that forum often tend to know more about this sort of thing.