As far as I know, trim tabs have always been an option. I bought a used 24 Offshore, (84 or 85, I forget).. no tabs. I installed them asap. Imo, every boat over 17' should have them.
If it were me, I would go for the 2000 Seafarer. Don't get me wrong, I liked the Offshore, (larger hull, more room) but the Seafarer has the Sea V2 hull, (better ride), decent room, more economical, easier to trailer and is much newer. I think you can do just as much, or go anywhere, with the Seafarer, as you could the Offshore. Becuase of it's extra weight, the Offshore might offer a "hair" more in protection, but it's definitely a trade off against the Sea V2 hull. The Seafarer will cut through a head sea better and the Offshore will have a wetter ride. Another draw back with the Offshore was, it would roll pretty bad when hit with a decent wave from the side, (broach). I think it was due to the high profile and narrow beam.