I've seen it done - Dual-boot between Win98 hebrew-enabled and Win98 Russian. The guy used some boot manager (I forget which).
edit - I just had an idea how to do it without any thrid-party software. It does require 2 physical HD's, let's assume Win98 English is installed on HD1:
- Connect HD2, disconnect HD1
- Install Win98 international as you normally would
- Connect both HD1 and HD2
Now, you can choose using the BIOS boot order:
"C,A,SCSI" - Win98 English, HD1=C, HD2=D
"D,A,SCSI" - Win98 International, HD2=C, HD1=D
You could have a second partition on the larger HD, which will appear as E on both configs. I wouldn't recommend any more partitions - will increase the thickness of your "alphabet soup".
-PJ