Sorry, I'm not Douglas ... but use all of the Hasselblad lenses on various cameras including the A900 ... they all work and are very good.
The best of the bunch from the 500 series leaf shutter lenses are the 40/4IF, 60/3.5, 100/3.5, 180/4 and 240SA and 350SA. You set them to the F setting on the shutter ring to disable the leaf shutter (That is what the F in CF stands for ... C for Central shutter and F for Focal plane.)
But older C type also work, as do CF, CFi and CFE versions. Best to stick with at least CF versions with their updated T* coatings. CFE versions have electronic data bus connections for use on some electronic Hasselblad cameras such as the 200 series and H cameras using the CF adapter ... they are usually more expensive and are a waste on the A900 using a dumb, non-e contact adapter.
All of the F series Zeiss focal plane shutter lenses also work. They do not have a leaf shutter in them and are strictly Focal Plane shutter lenses with relatively fast apertures for MF lenses. This series features a 50/2.8, 80/2.8, 110/2, 150/2.8, 250/4 and 350/4 ... these can be F or FE versions for use on an A900. F stands for Focal Plane and E stands for the Electronic data bus connections when used on Hasselblad 200 series cameras.
The Zeiss 120/4 Macro is not like 35mm macros that focus 1 to 1. You have to use extension tubes or a bellows to get true macro. Macro in this case means it is optimized for close focusing and flatness of field ... it is less used at infinity for this reason.