The interesting thing about waterfalls is that the lead up doesn't have to be straight - Only the immediate tiles next to it have to be alligned. Here is a quick mock up of a waterfall scene which shows how mountains can retain a 'natural' look and still have the ability to have a waterfall.
As for the tiles, hover over your tileset in A-Map and look at the bottom-left corner of the program, it should state: "Block: Y, Offset: 0xZ". Just scroll over the tiles until you find the numbers you want and everything should be fine. The tiles you are looking for will have the wrong type of water underneath them (the light blue and flat one), but I'm sure you can make a new tile with the same attributes but with the correct water :3
Hey just following up your review on the map thread:
You mentioned the mountains at the top were out of place, I agree but how do you make them look natural well using the waterfall tile as it needs to be a straight drop.
Also how do I know witch tiles are 224 to 226?
Sorry about all this I am kind of new. (working on my first hack anyway) and if i posted this on the review thread it would just get deleted