Wow..It's great you saw the peice on the TV and want to get involved!!
They are a whole bunch of bockers in wales...the group is called welsh power bockers.
their part of the forum is here
http://www.projumpforum.co.uk/index.php?board=56.0 have a word with them and keep an eye out for meets. Although I am not sure how active they are on this forum..Somebody will help you out here.
Dont forget about capital bocking too. it is being held in cardiff this year so yes you are the right place to be.
http://www.projumpforum.co.uk/index.php?topic=961.0It's fine to buy before you try.. I am not sure you can try before you buy in this country
Things to get sorted before you start.. have you got the right weight springs. Poeple sometimes rush to get them and dont know that they even have springs for different weights and that you should get them at least 10kg over your weight.
Next thing is have you got protection? wrist guards are totally essential and the knee and elbow pads too.
Only other advise is to go through the whole of the mods section. Essential mods in my eyes being taping the springs and tire socks. i really recomend you tape your springs before you start as they are easily damaged.
After all that! HAVE FUN!!!
spud