As I thought about it, the Wista RF should work as well as a Horseman or Linhof, one advantage of a Linhof is support, they are repairable to a certain extent. The RF has 3 built in cams for 135, 150 and 180, and can be adjusted to work with any 135, 150 and 180 lens, the 135 is some what wide for 4X5 is long for 6X9. Looks like there is 6X9 back, the manual I found on line for the RF has only the first 7 pages. Again the big disadvantage of the Wista is that when shooting 6X9 there is are built in cams for 65 to 120 lens, which are lens most useful when shooting on the street hand held.