The 38's product family included the M-30 and M-35. There was an expander for the M-35 called the M-35EX, which is hardly ever seen, but I saw one on Ebay a few weeks ago.
The TSR-8's vintage model was typically paired with the M-308/312/320. The later "B" revision added phantom power.
I guess the 58's product family probably included the M-512 and M-520.
All these boards, above, would be classic, vintage style mixers with VU meters.
There is the Tascam 200 series mixers, like
the M-208/216/224. These are highly capable boards, also VU-meter type.
The M-600 is a VU-style 32/16 board, that's h-u-g-e.
There are other LED-meter type Tascam mixers that would be functional with an 8-track reel system. Model numbers that come to mind are the M-1508, M-1516,
M-2524, M-2600, M-3500,
M-3700.
Implied or obvious, is that the higher the model number goes, the higher in complexity, size and cost.
There are other non-Tascam boards you could mate up with Tascam recorders, I suppose, but a Tascam board is typically the best match to a Tascam recorder. Likewise for any recorder, that a brand similarity helps sometimes when matching components.
A Fostex-recorder/Fostex-mixer solution is good too, if you want to go that way. Fostex analog has it's niche, but Tascam analogs were way more heavy duty construction, & higher quality, all around. [IMO/YMMV].
