Minds out of the gutter please, I am talking about horses! 
As I may have mentioned before, (sorry to go on about it!) I am back on the hunt for a horse on loan. I am only 5 foot 3, and 9 st 7lb ish, so I had thought of getting something around 15 2hh. The trouble is every horse I have seen advertised seems to be 16 2 hh or more.
I have recently been riding a 17 hh horse, and although from the ground he looks ridiculously big, once on board his size doesn't really seem to be an issue. I was wondering what people think is an acceptable size horse to rider, or does it actually not matter? Thanks.