Just a couple notes on your wish list.
If your budget will allow, you may wish for the 50mm, 'ULD' lens, instead of the standard 50mm.
APO glass, with Floating Element design. Better edge-to-edge sharpness then the standard 50mm.
http://www.bhphotovideo.com/c/product/154472-REG/Mamiya_212_314_Super_Wide_Angle_50mm.html
Also, so that you're not jumping through a bunch of different hoops regarding the prism...ie,
wasting your money on something that won't work. Basically, the only or best prism for the
RZ II, is the Prism II. Example below. Note...this is the prism with the control knobs on the top.
http://www.bhphotovideo.com/c/product/33801-REG/Mamiya_212_407_AE_Prism_Finder_II.html
The RZ/PD Prism, (or Prism 2(?) as you call it), cannot be used on the RZ II body.
It works on the original RZ Pro body...but not on the Pro II body.
The AE prism for the original RZ Pro, must be modified for use on the Pro II.
This prism has the controls on the side.
http://www.bhphotovideo.com/c/product/800885470-USE/Mamiya_212403_AE_Prism_Finder_Metered.html
Another thread from APUG may be of help to you.
(there was a url link here which no longer exists)
Marc