Thanks for the help, once you have worked it out from their website it’s then another job to decipher how CRC or Wiggle have listed them so you end up with the right ones!
For example, Wiggle have 3 racing ralphs listed – a snakeskin, a dual compound performance (both of which match up exactly with the Schwalbe website) but then also just an Evo version – it’s not lightskin and it’s not snakeskin, so which version is it?
http://www.wiggle.co.uk/schwalbe-racing-ralph-evolution-folding-29er-mtb-tyre/
Probably I will end up going for the snakeskin option to save hassle as its the first time i’m trying tubeless.