Thanks for your interest in Feisol tripods from Really Big Cameras.
Before I answer your questions, I have several for you.
1) How tall are you? This will make a difference in which tripod I recommend.
2) What is the longest lens you use on your ARCA-SWISS and Canham?
3) Do you use any unusually big, heavy lenses on either camera (like a fast portrait lens, or a 300mm in a Copal No. 3 shutter)?
4) How important is compact folded size? This will be the deciding factor in choosing between 3-section or 4-section legs.
5) Do you already own and ARCA-SWISS Z1, or are you in the market for a ballhead of similar size, quality and strength? There are other models that fit better within the reverse folded legs of the Feisol tripods. There are also brands that, in spite of being smaller than the ARCA-SWISS, don't fit at all within the reverse folded legs of the Feisol tripods. It's not just a question of size, the locations of the control knobs are even more important.
6) Do you plan to use this tripod with, or without a center column? The addition of the center column changes how the ballhead fits within the reverse folded legs. Some ballheads that won't fit without the center column fit fine with the center column installed.
7) If you do own the Z1, which version do you have, and especially which style of QR clamp (knob driven or flip-lock)? This is important, as it's the QR clamp on the older ARCA-SWISS B1 that presents the most difficulty in fitting that head within the reverse folded legs of the Feisol tripods.
8) Do you have any plans to move up in format to 5x7, or 8x10? If so, would you like to use the same tripod for the larger format?
Sorry to ask so many questions, but I don't like to make specific recommendations unless I have all the details. Fortunately, I'm also an ARCA-SWISS shooter. So, I'm very familiar with the system and have used it, in various format configurations, on several different Feisol tripod models.
Really Big Cameras