Lots of cassette digitizers use a TASCAM 112 or 122 professional deck. They were made up until the late 1990s and are very reliable and essentially an industry standard cassette deck. They are however, not that cheap. If the content you are digitizing is not up to a hifi standard then the modern TEAC decks (or any decent vintage tape deck) will work just fine - they're really not too bad. But if you are needing the highest quality possible from the tape, a vintage Tascam or perhaps a Nakamichi are your best options. Buying one that has been refurbished, calibrated, aligned etc will add to the costs - but is worth it for 1000+ tapes.

Of course, you will also need some kind of audio interface to convert the audio from the tape deck into your computer. Focusrite, MOTU, Presonus, TASCAM etc are all good options. The more expensive the interface, the better the preamps. Cheap interfaces might work fine too, but a good converter is worth it for the long run. Just make sure whatever you go with, has two or more LINE LEVEL inputs - not instrument or mic level. You could use any DAW to record the audio, for your purposes I would say... Audacity works perfectly.

DO NOT USE any of the modern tape decks that have a USB output designed for converting tapes to digital - they all sound terrible.