RE: evo XTV --- where toget a bigger fin
Sorry but I cant help you with exactly where you can find a Drake Natural fin. I do think the 25 or 26 cm version would indeed suit you very fine. Which one of these depend on just how small you fins the original 23. One of the nice things about the Drake Natural line is how smooth the transition between sizes are.
That said, I True Ames will probably work well to but I can't helt you with the sizing on that one. The Drake Natural fins sail small for their depth (and probably small for their area as well) so you can't directly compare to the same size of another model.