Further to Steve's post about making a custom pad I thought it might be best to post in here
Anyway it looks as though SCAN will be stocking "some" of the pads however I thought I would see in here which ones are more popular
The pads can be viewed here:
http://store.gameshark.net/brand/sfiv.htm
Let me know which ones you prefer and I shall request our purchasing team to get them set up on the system