You have not listed my favorite racer/cruiser in this general size range, the Laser 28. These are Bruce Farr designed, Kevlar hulled, 4100 lb, fractionally rigged sloops. I went through the same search that you but back in 1988 which lead me to buy a Laser 28 which I raced, cruised and daysailed for 11 years. These are super little boats. They race well under PHRF (129 Chesapeake Std rating) and MORC. They can be raced with crews as small as 4 and as large as 6 or 7 (five being pretty optimal). Their fractional rig means a smaller less expensive sail inventory and simplier depowering and dialing in. I have successfully raced these boats with very inexperienced crews, talking them around the course. That said these boats really reward a skillful crew.
All halyards and control lines are lead aft except the spin pole which is controlled from the mast because the Laser uses a boom mounted pole launcher.
As cruisers they have a very nice, open layout with lots of storage and a very workable and innovative layout and detailing. They have roughly 5''10 headroom at the galley. Most had pressure water and a shower although I doubt anyone actually use the showers. They have a large cockpit with coamings. The came standard with a small Buhk diesel that was very adequate to push the boat. We typically would cruise ours for a week to 11 days each summer with plenty of storage for what ever we needed. There is a large locker aft of the head which is actually large enough to carry a pair of full sized bicycles and an inflatable dinghy.
These are excellent light air boats and are surprisingly good heavy air boats as well. My wife and I were caught in a storm that pegged wind indicators near us at 65 knots. Frankly these were survival conditions for the boat but the boat did extremely well. We were able to beat clear of the river that we were in and gain searoom to reach off. Several heavier cruising boats near us could not make headway and were driven ashore on the lee shore of the river.
These are remarkably tough boats that sail extremely well. I like them so much that when I replaced my Laser 28 I bought a Farr 11.6 which is a 10 foot longer version of the same general design.
Regarding the other choices mentioned above and a few other ideas thrown in as well:
J24: These are good little boats that still have large fleets in some areas. They offer excellent one design racing where fleets are available and there is a lot of info about how to race these boats out there. They don''t have much of an interior. I have always found them uncomfortable to race and frankly not all that much fun. I would strongly recommend a J-22 instead which is what I race our beer can series on these days.
S2 7.9: These are good MORC boats. They offer reasonably good build quality.
J80: I never have liked these boats. Its funny because I like J-27''s which I raced on for 3-4 years and I like J105 which I campaigned on for a year But the J-80 has always seemed like a dud to me.
S2 9.1: These are good all around boats that are competitive in MORC and PHRF. They like lots of wind but are less fond of chop. They take big crews to race well. They have a very nice interior. 9.1''s are notorious for Mast step, and deck core problems.
S2 9.2: These are not race boats by anyone''s objective standards. I never have thought much of the design or build quality of these boats.
C&C 29: Nice boats but not really racers. They can be raced in PHRF at the club level.
Cal 9.2: Old Ron Holland IOR era design. They are pretty good upwind but not so hot off of the wind. Racing one means an expensive sail inventory, a big well trained crew and an uphill fight.
J30: Sort of a big J-24. There was a huge fleet of these around the Chesapeake. I never liked racing these boats. They were meant as old style racer-cruisers with lots of rail meat, and so the cockpit and deck really do not work well as a race boat. They do have a nice interior but racing one is as thrilling as kissing your sister. I would sooner suggest that you look at a J-29 which is the same hull but a more race oriented masthead rig, but much more spartan interior.
Hunter 31: Not a race boat. Not a bad coastal cruiser.
Kirby 25: These are a Canadian answer to the J-24. I owned one of these as well and they are very nice little boats that can be a real blast to race.
Kirby 30. These are the Canadian answer to the J-29/J-30. I am a very big fan of these boats in a lot of ways. They are competitive under PHRf and if converted to a masthead rig, under MORC.
Lancer: Never was a ''racer''/cruiser. They certainly are not race boats and frankly with all due respect to Jim, in standard form are not exactly good cruisers.