Post a noter on the usaca.info website to dave Carlson when you are ready to add a spinnaker to the rig. He and others in the class have boats with a spi option.
In terms of adding a spi to an A-cat later on ... Im not so sure that it would be a good idea since the hulls and overall design of the A-cats arent made to handle the extra weight that a spi would add plus the balance would be off and Im sure that nosedives would be an issue.
But I still think that the Nacra A3 is one of my top choices.
But I still have one more cat to ask about (sorry for all the questions) .. The Nacra I17 .. the fact that its a singlehandle cat with a spi is interesting so does any1 recommend it?