A 486 DX2 66 MHz(preferably with a turbo button to downgrade to 33MHz), 16mb of Ram, and a Soundblaster 16 should be more than sufficient to run older DOS games. Run Dos 6.22 as specified above and you shouldn't have any issues. If you're planning on running the original disks from Sierra, make sure you have the patch disks/files.

Don't forget an older IDE HD.