I fly an asym from a sock on Ananda, off of a 2' carbon fiber aftermarket sprit with a bobstay to take the sprit tension.

I considered a furling system but my sailmaker was pretty pessimistic about a furler working on the J-30 - the spinnaker halyard exits basically at the forestay, which is way too close. A furler needs at least 6-8 inches of clearance to operate properly and preferably even more.

The sock is great, though, and the sail flies beautifully:

[Linked Image from i.imgur.com]/

[Linked Image from i.imgur.com]