I have an Induro AT113 which I use with a Gitzo or a Manfrotto ball head. It's fine for travel, and it worked just fine with my Rolleiflex 2.8E doing 16-30 second exposures at night.

Given that, were space (and budget) less of a consideration, I'd opt for something a bit beefier just because. Any compact tripod in that size range will feel a little wiggly when extended. I would NOT use it with the center column fully extended (which wasn't really an issue when shooting the Rollei, which only has the waist-level finder).

The ball heads I have are older models that they don't make anymore, but the equivalents are the Gitzo 2750QR or the Manfrotto 496RC2. Both are light-weight, compact, and will hold your Hassy with ease. The old Manfrotto ball head I have has a single lock for the ball as well as for panning (a BAD idea), but I think the new one has them separated. The Gitzo has separate controls for panning and for the tilt of the ball, as well as friction adjustment. IF you go with a ball head, I would highly recommend getting one that has those two controls (ball positioning and ball friction) separated, to make it easier to control large and fine movements).