I race in the Beer Can series on a J-22 which I consider one of the most fun boats to race of anything that I have ever sailed. They are not all that fast but they really are team building little boats and a blast to sail. But that''s off of the topic. I brought up your question on board and we thought that these are such extremely different boats that you really need to try to sail both boats to understand what really suits your needs. The opinion was unanimous that none of us likes the J-80 but the Melges is such a specialized and skill intensive boat that it will either knock your socks off or else turn you off right away.
Two of us have sailed Kirby 30''s and think these are still very good boats. Around here a number of Kirby 30''s have gone to masthead
rigs and doen well in MORC as well as PHRF.
We also thought that you might try to find out what local one design classes are available to race in. As much as I enjoy racing my boat in PHRF, racing is really a lot more fun and the learning curve steeper in a one design class. I don''t know if the Laser 28''s still have a one design class up on the lakes but these are very nice boats to race one design and can be sailed with about the same size crew as a J-80.
Good luck,
Jeff