I don't think that having a Leica scope and looking for a camera will differ from any other scope brand. The scope is not the issue but rather the adapter you find to match your scope. Leica might already have one. If not, check out
www.digiscopeadapter.com. Many times you don't need an adapter so keep that in mind. It just depends on what you want from your images. Usually dig-scoping images will not match up to a DSLR + 600 lens etc, so also keep that in mind. To me, digi-scoping is more of a 'sport' than photography with a huge lens. Given the equipment and the dollars to purchase a camera plus lens, anyone can take excellent shots now-a-days but digital-scoping still takes skill and involves a learning curve.
For cameras, personally I prefer 'point and shoots' with a small optical zoom so it takes away vignetting. Frankly there is no need to over-complicate an already difficult task. A point and shoot works wonders. I have been digi-scoping (since the mid 90's) prior to when the term 'digi-scoping' was coined so have been thru many cameras....point and shoot, up to DSLR's. I have mainly played with Swarovski scopes but started off with a cheap Bushnell.
At the moment I am digiscoping with a Nikon Cool Pix P310. Other options if you want to be 'latest and greatest' might be small Sony RX100 series or Canon G series etc. A nice mid-level might be a Panasonic Lumix ZS50 series. But I prefer that 5 year old Nikon. Again, more importantly to you should be the adapter you have for your scope. You can get 'ok' images without an adapter but in order to get good images, you need one. jim
see following blogs if interested....
http://www.atlanticaudubonsociety.com/digiscoping.html