MikeT: The soil comes in three colors... black-gray sand, yellow-brown sand and gray-white sand, depending on humus content. It is either wet, which holds its form; or dry, which flows like dunes in the Sahara. There was no serious thought given to spraying directly on the sand because of the instability, the need to slope the sides (losing volume), and the extra quantity of polyurea that would be required. Probably even more reasons.
I did not go the CIM route because (1) I never thought about it and (2) I do not know of any pondbuilders using the technique. I became convinced after 5 months that I had to have it done by someone I would not have to supervise. I dealt with a number of garden pond builders & swimming pool builders, etc., but I was having to teach them about filtration systems etc. In my situation, it was not going to happen unless I retained someone with experience building a system of the sort I wanted. ... My favorite: The guy who assured me that he could build whatever I wanted, and then got a foggy look when I said I wanted a gravity fed filtration system. You could tell that he was trying to figure out how gravity gets into a filter.
Don't have sketches to post, but will think about what I might be able to do.
As for buying expensive koi, well, not any time soon. I have a lot to learn before taking on that responsibility. What is coming are 6 Showa. One is a special gal I've admired for at least 3 years which is available because her owner has upgraded his collection. The other 5 are from a domestic breeder (!?!! .. not even Japanese!), and are mostly very modestly priced koi. Each is a different type of Showa. Of my current 9 koi, 4 are Showa. With 10 different sorts of Showa, I'm hoping to learn a lot about their development in Florida in the years ahead ... and I hope to have the space not to have to find homes just because the pond is being outgrown.
The rest of your questions will be answered as the project progresses, so I'll not spoil the "show" right now.
