Good morning, Michael;
In the Minolta line, anything, from the SR-7 through the SR-T series, which has the Mirror Lock-Up (MLU), and a "B" setting on the shutter speed dial, will work fine. Do not worry about the accuracy of the timed speeds on the camera, as long as the shutter works properly when opened and closed with a cable release on "B." You will be using exposure times from a few seconds to perhaps hours with a tracking German Equatorial Mount and/or guiding. The one place where you might use the timed settings on the shutter speed dial is with lunar photography. Once you get into the Minolta X Series of cameras, they require batteries that will be affected by the frequent cold temperatures encountered while hanging off the back of your telescope, especially during the winter when we have reasonably long times available for photography at night, and they probably will not have an MLU. This is a case where the simple older mechanical cameras are still preferred, and they probably will be cheaper. The Anglefinder or Anglefinder V helps getting the focus right and puts the eyeport in a position that is much more comfortable to use with your telescope.
While I have hung one of my Minolta SR-T 102 bodies off the back of my little telescope, I actually prefer the Nikon F2 with the Type M Focusing Screen and the DW-2 Magnifying Finder (6x). The Type M Screen with the cross hairs for aerial image focusing does help in getting the focusing right where you want it. It is just a little more convenient than using the ground glass collar area on the Minolta viewfinder screen. Not too much more convenient, but there is a difference.
