The 4xStore went out of business, and was replaced by the "On & Off Road Store".
Yoy can try this # - it may still work: 615-791-1247
Shannon should be able to get you in contact with Jimmy or Archie of SFI.
If not, you could try buying them from Tennessee Off Road: 615-248-8638
Ask for Chuck at TN Off Road and he can get you the info on SFI.
I personally don't recommend them for several reasons, but here is the contact info you wanted anyway...
Davids 4x4 Page