Are you looking for something tunable only, or wideband? As far as monitor are concerned, the analog Belars are OK, (AMM-1, -2, -3), and are good to 30 MHz. The AM wizard was probably the best one they made (AMMA-1), also good to 30 MHz. The Inovonics ones are AM band only, usually only to 1710 KHz, models 520, and 525 were adequate. TFT made some wideband ones as well, but documentation is spotty and with the company gone now, if you need a book, your on your own. Older Harris monitors were cool, I like the AM-90 the best. It had a cool plasma display.
The Belars pop up on ebay from time to time, and at hamfests. Be prepared to do some rework on them.
If you want to go analog processing, CRL's are fairly common. I have two Amigo AM's as backup units to my stereo tool setup. The inovonics processors weren't that bad, although the clippers in them were not filtered, so you can't really push them that hard before they get grungy. The CRL's are the same way. Top shelf is probably the 9100A (B was the stereo version with the right cards), although most of them are over 30 years old and will need some love. They can be a devil to get running again as some of the VCA's you cant get anymore.
+-RH