A most interesting proposition, indeed!
Quid pro quo, good sir: I put together a little map this weekend designed for just such a 10 player game (115 land/25 uw provs, 8 land/2 uw players). This map is also in need of some testing.
Perhaps a gentlemen's agreement can be arranged? Consider the map, and I shall consider the game?
Here is a screenshot, though you'll have to wrap-it-around in your head:
Upon close inspection by monocle, you'll see it too has several silly features included strictly for spice:
1) It's "planetary," i.e. east-west wraparound with "polar" connectivity at the poles, much like the map in my signature.
2) It's made of a number of small islands, and therefore has a large number of chokepoints, by design. This is particularly true in the ocean, which is usually strategically neglected by mapmakers.
3) Sailing is consequently very strategically important. Also by design. Who doesn't like boats?
4) To compensate, the islands are connected by underwater passageways...these passageways are cave provinces.
Let me know, my good man.