First off, I am not a spinnaker expert, but i have been doing alot of research recently about them because I just rigged one on my cat.
Yes, the front of the sail would attach near the bow, and the other side would be sheeted to some point back near the rear of the boat. Where would depend alot on the size of the sail. This video is a good example of what kind of spin I am talking about.
http://www.youtube.com/watch?v=Lvdnrt39b8U
I can't be sure, but I have always heard that asymetrical spins placed lower loads on the mast, but I don't have any way to confirm that. If you keep the main sheeted in pretty tight it would add support to your mast. Plus once again comparing this to a cat rig, it would be best to not attach it to the very top of the mast. Maybe just over 3/4 of the way up that mast. That limits you to a smaller sail but also keeps the loads alot lower on the mast where it is stronger.
Here is a very crude drawing of what I picture
red=mainsail
yellow= spinnaker
Black dots on rear beam= block for spinnaker
Blue= spinnaker sheet
You would keep the mainsail in pretty tight like we do on our cats to provide support for your mast, and you would not go straight downwind, you would tack or gybe downwind just like we do on our cats.
As you can see the spin would come back past the mast but as you gybed you would let it blow out front and then pull it to the other side.
The sheet as you can see will be attached at the clew of the sail then would be let backwards to the block then through the other block then back around to the clew again. Thus giving you a continous sheet which= less mess and much easier to use.
This could all be rigged very easily to be snuffed through the front hatch on the AI, if you look at how cat spins are snuffed you will see that it would be easy to rig a system that would function as a halyard and a snuffer line.
Well, that might be an overload of info. Just post any questions you have and I will try and answer them to the best of my ability. I would like to see this work.[/img]