The CVS version of OpenCBM supports the Mac. You have to compile it yourself, but it has a MacPorts portfile included so setting up is no big deal.
Both the XU1541 and the
XUM1541 devices work on the Mac with OpenCBM. However, I would recommend the XUM1541 device because it supports more features (including parallel transfers and in near future even nibbling) and the project is still in active development.
I have written a detailed tutorial on how to setup and use OpenCBM on your Mac:
OpenCBM on Mac