For boats the age you are looking at, All could potentially have some major issues, it is probably best to try and find a 30'ish foot boat that has been well taken care of etc vs trying to find a particular boat.
With that in mind, When we got current boat 3 yrs ago, I was thinking Cats, Newports, San Juan, C&C from the late 70's into the 80's. Was told to stay away from Jeannuea and Benateau, Lo and Behold, hopped on a Jeanneau Arcadia, wife fell in love, hated the others mentioned, we ought her from the original owner. Yes a few things to do, but a nice boat. Also a bit faster than the above boats too. PHRF as low as 155 in upper Cheasapeak, to as low as 191 in BC PHRF area. Generally speaking, faster by about 10-15 secs over boats mentioned, and about 20-30 secs slower than a J 30.
All are good old boats for what they were designed for.
She drives me boat,
I drives me dinghy!