Non-standard bottom row = no keycap sets will fit completely. I don't know why the "gamer" brand companies continue to do this. Logitech G710+, Razer Blackwidow, Corsair K70 & K90, Roccat Ryos, etc, etc.
If you're buying a board with MX switches, swapping caps is a very attractive feature, since there are so many sets available that can fit. But not on one of these monstrosities.
Anyhow, ranting over. You can fit a set that has a WinKeyLess kit and a few extra bottom row 1x caps, but you're going to have to keep using the stock spacebar with them, so that really limits the colours / profiles you can use.
Here is a site with a few sets listed that you can browse to get an idea of what's out there:
http://keypuller.com/Read more here:
http://deskthority.net/wiki/Keycaphttp://deskthority.net/wiki/Keycap_constructionhttp://deskthority.net/wiki/Keyboard_profileThe ones on your Ryos are likely OEM profile, so most of the better quality sets won't quite match (Cherry profile, SA profile, etc), but if you don't mind the height of the spacebar being different to the rest of the caps, you can fit any of them.
If you don't like smooth caps, you may like PBT material caps (which have a different surface texture to ABS and are harder wearing), the best of which are thick and have dyesubbed legends like the Leopold sets available from widebasket on eBay. Be aware that caps can get expensive and it's addictive finding and buying new sets... refer to my sig...