My choice would be the Cimbali as it has a larger boiler and is built like a tank.
If youre talking the old Bezzera Minibar, it has a horizontal 2l boiler identical to the BZ35. The BZ99 has a smaller vertical boiler and is smaller and built mainly for domestic use. Its still a good machine, but Id put the La Cimbali above it in terms of build quality and robustness.
That said, both machines should be fine and parts are readily available for both.