The closest you will get is with the ronstan "Low profile swivel with roller fairlead"
Here is what it looks like on my boat
Here is the murrays catalog page. Part number is 01-3130
Price is listed at $130.00 now "I THINK" that would be for two cause I payed $70.00 for each at my local hobie dealer.
part letter = (F)
Hobie also has these listed in there latest catalog on page 34. Lo-profile jib block part # 1075 with cammatic wich is the one I listed above in the photo or hobie part # 1076 without cammatic. If you are to upgrade get it with cammatic.
You can always go the "upgrade the front crossbeam bar with an intagrated jib car traveler" wich would be more expensive.
Hobie part number for the front beam is 25131910 at $234.70 without the blocks
Hope this helped