From what i gather both k-tec and RS are meant to be pretty good. It's just how close you are to one or the other. I'm in lincolnshire so not far from you and i'm based up in yorkshire so it'll be RS for me. Bit strange with them though as i went on their site and couldnt find an option for clio 197 tuning, it was only hearing about them on here that i found out they map 197's. I'm going for the same as you mate but in two minds about going decat as i want the car to run properly and not throw up error codes all the time.
I'll be speaking to RS soon but just waiting to get the spacers and geometry done first. I'd def say a map is worth going for though, some people say they can't tell much difference between the 197 and the 200 which is fair enough but i felt i could. 200 was much smoother and definatly quicker. At the end of the day i think they had that many people complaining about the 197 map that they actually did something about it and changed it for the 200.
Have you had a quote from RS for the filter and map?