I'd probably suggest a camera for one or the other of deep sky/planetary, as I think you'll compromise lots if you end up in between, and may be disappointed in one direction or the other. Also on the computer/laptop you need for capture - a little notebook/tablet works for deep sky (long battery life key), but a faster machine helps for grabbing planetary frames (high performance, shorter battery).
I have the
ASI 185MC for planetary - works very well with Firecapture and seems to produce good images with my scope. Can't comment on mono or other ASI cameras, though there are some very good deep sky images coming out of the ASI 1600...