The camera has no fancy flash controls at all, so no TTL etc. Any flash will be as good as any other for straight flash, subject of course to distance (more distance requires more power).
You will probably want to use the A setting. You need to read the manual (available on Mecablitz web site) very carefully, because different flashes offer different degrees of flexibility when choosing the aperture in A mode.
If you have other cameras with some flash automation, you might be interested in an SCA module which works with this flash.
Bounce flash is useful, so get a flash that tilts to the ceiling. If you want portrait orientation (vertical) using bounce flash, swivel is needed.
I have a Metz 44MZ-2 (which tilts but does not swivel) that I use with a Mamiya 6 and a Rolleiflex. Both are square, so I don't need swivel for those cameras, but the 54MZ-4 does swivel. Had I bought that instead, I would have gotten SCA modules for a couple of non-square TTL cameras that I have. I regret not investigating more thoroughly before purchasing.