Hi Jake,
Thanks for your comments. I think you covered Jon's questions very well.
The only thing I would add are some PNs to relate relative boat performance of other boardless beach cats. SC 17 PN=73.3, Hobie 16 PN=76.1, P16 PN=77.5, P18 PN=74.9, Dart 18 PN=76.9, N5.0 PN=76.4 and ARC17 w/spi=70. The SC 17 can be upgraded to an ARC 17 if you want to with a factory kit. The kit includes a self tacking jib, a square top mainsail and a spinnaker and pole. If you usually sail single handed, the self tacking jib would be a big help by itself.
Good Sailing,
Bill