OK, Im no expert, but I have kept a bimac before, and I would recommend them as the appropriate species. Contact Flying Fish Express. They sometimes have captive raised bimacs - your best bet. Or if your in the DFW area, I know a local place that frequently has them.
Other specifics:
Filter: as much as possible - skimmer is paramount in case your ceph inks and because they are messy eaters TANK MUST HAVE BEEN SEASONED BEFORE PUTTING ANY OCTO INTO IT - I cannot emphasize that enough
Rock: as much as you want, as long as the octo has plenty of places to hide - PVC pipe makes good hiding places too
Food: live crawdads are what I fed mine - they will also take raw frozen foods such as shrimp or live shrimp, snails, hermit crabs, etc. - babies will need extra care though
Tank size: the min. size for a bimac is 30 gal - I kept mine in a 120
Keep in mind that cephs don't live long and they must be kept alone - they will be stressed by or eat any tankmates except cukes, urchins os stars. Bimacs live about a year, and unless you get a newly hatched one, don't count on yours living for more than a few months.
Ceph's rock! But they require a lot of experience, a lot of patience and not a small investment if you want to do it right. Good luck, and hopefully others will chime in with more info!
HTH