I'm going back to analogs. We have been very happy with a digital spec. They will also accept B-L spec tubes or regular test tubes or square cuvettes. They use 1 cm cuvettes and the light beam is very small in profile, so the cuvettes usually need only about 1 cm depth of liquid. If you want analog output for chart recorders, an extra card will be required.
Digital output is standard.
If you want a spectrophotometer which will scan wavelengths and demonstrate absorption spectra, I recommend the Shimadzu UV1201. Really a nice instrument, once you get used to the keypad commands. We used Spec 20's for years and have found that failing bulbs can give rise to weirdness that may not be expected to arise from the bulb. We have just purchased about 15 new models and they are behaving very well. The Spec 20's still function but many stop probably because of bulb failure.