Re: Which Cymbals to add for my Rolands ??
The Roland CY-12C and CY-14C are both dual-zone cymbals(bow, edge), made to be used as a crash, and both will work with your TD-9.
The Roland CY-15R and CY-13R are both three-zone cymbals(bow, bell, edge), and made to be used as a ride. However, they need 2 cables to make all three sounds. The CY-13R yours comes with will have 2 cables for it, but you won't be able to add another three-zone cymbal. You could still buy another one and only plug one cable into it, but it would only be dual-zone like the crash and hi-hat cymbals yours will come with, so it would be a little pointless since these two are more expensive.
There's also the CY-12R/C that can be used as a three-zone ride(but would require 2 cables) or a dual-zone crash(one cable).
Any of those 5 cymbals will work just fine, I just wanted to explain the differences, and to make sure you know that if you buy another three-zone cymbal, you'll only be able to use two of the zones. There are also two cheaper cymbals, the CY-8 and CY-5, but I wouldn't recommend getting those.
The number in the model name indicates the diameter in inches. So the CY-14C is 14". Look on ebay for some used ones. The easiest and cheapest one to get would be the CY-12R/C, and I think that's just because there's more of them around, but they aren't any lower quality than the others.