If you don't really have a need for the horizontal arm, you can save some money by getting the 055XB instead of of the PROB. I think the arms are overrated in their practicality, especially with the Manfrotto, which only goes horizontal. The load rating and stability go down rapidly the more you extend the arm from the tripod's centerline. I do have a tripod with a multi-angle column-a Giottos MT9371, but it's big enough and heavy enough to handle it. It's one size up from the 055 size category. Giottos also make tripods equivalent to the 055 which compare very well, seem to be a little less expensive, and which I personally prefer.
One thing concerning height-with your MF camera, if you're using the waist level finder, you won't have it as high as with your 35mm. So with the heavier camera you'll be able to increase stability by having the tripod legs not extended as much.
Regarding the head-consider a standard 3-way pan-tilt head; a high quality one is much cheaper than a high quality ball head. I like the Bogen 3028/Manfrotto 115. It's very inexpensive used. Its sections can be worked around so that a vertical shot with your 35mm will have the camera almost perfectly over the tripod's centerline, unless you're using a winder, in which case it will still be better than with most 3-ways or ball heads. In addition, the sections can be worked around to enable it to hold the camera off the tripod's centerline farther than a regular 3-way or ball head-enough that I like that better than an adjustable angle column for a lot of my angled or straight-down shooting.
If you later decide you would rather have a ball head, you can start saving up for a really good one, then sell off the 3-way. I have both, and like them both, but if I had to choose, I'd keep my 3-way.