i'm not a serious biker so i don't know how well this will work for you (i think it's just a little spring in it). i have a fork for a 16" that i'm using a 20" wheel on. it works if the tire is no more than 20x1.5. i need to have the brake attactment points moved or get brave enough to try it myself, but overall it seems like a good deal.
here's one on a semi recumbent cruiser i'm working on, but i have another for the someday full on recumbent i want to do.
check ebay for seller lixandria. they go pretty cheap if no one bids. she's in canada so the shipping is a little higher, but still a good deal.