"I'm leaning toward the S900..."
Good choice, Zuki. I think moving up from a fantastic keyboard like the 3k to the S900 will be just what you need to keep that enthusiasm going.
It sounds as if most, if not all your hard work on the 3k can be successfully transferred over to the S900, so do that first and then tweak only what needs tweaking. After you become familiar with the S900 you can go back and change those 3k items you want to update. Go for it, pal!
Let us know how your 3k repair comes along. Maybe one of us
would be interested if the repair is successful and the price stays right.