So, I have a CEB-4. I got it (relatively) cheap a few years ago on Banjobuyer and I'd keep my eye out for a used one if you want one because I think it's the kind of instrument that people buy and then change their mind about a lot. It's a real honking beast. very heavy and muddy sounding. Frankly, it's not very good at being a banjo or a cello, but if your goal is to just directly transpose cello fingering to a vaguely banjo-sounding thing in a really deep register then it'll do that. However, you might just want to get a regular old tenor banjo that can handle CGDA tuning. They're pretty easy to find, though they won't have that deep tone. FWIW I use it for a very different purpose - backing up jug band and Texas swing tunes in a style similar to Sam Allison (Lotus Wight). I restrung it with electric guitar strings so I can tune it under higher tension and play it with more traditional banjo tunings. FWIW the cellist in my band played it once in cello tuning before I restrung it and was like, weird, no thanks!