If you have a PowerQuest PartitionMagic, you can knock back a couple of gig on your hard drive and mount a DOS 7 primary partition, then access it with the boot manager. You mount your game so it runs from the DOS partition.
If you get an old 8 to 20 GB HD, you can mount it and partition it as your second HD and either make it all FAT32 for DOS7.1 and (optionally) Win98, or you can make it a few GB for DOS and the re3st NTFS for your main OS...