fluorescent microscope recommendations

Hello -

I am starting to look at options for an upright fluorescent microscope. I currently have an old Zeiss with TRITC and GFP filter cubes but would like a motorized focus drive so that I can do Z-stacks and more options for filters. I have a Nikon camera and software to use on a dissecting microscope so I am tempted to stay with Nikon, but there are elements of the software that are not very user friendly. My budget is around $40,000. I would appreciate any suggestions (or warnings) that you might have.