This is what you want:
Nashbar Rigid 26" Mountain Bike Fork
I have them on 2 of my bikes, including one that originally had a low-end Rock Shox suspension fork ca. mid-90's. Unfortunately it seems to be back ordered, but you may be able to find the same fork on Amazon or eBay or elsewhere that Nashbar sells.
V-brakes on this one:
Disc brakes on this one: