The reviews I heard about zipzoomfly is absolutely terrible.
Well you're reading the wrong reviews then. I've ordered from them numerous times and not once have I ever had a problem. Everytime I've ordered something from them is because it was cheaper than neweggs too.
Aright, if my conversion is right, 100 pounds is about $150US....
That won't get you high performance gaming and high quality OC'ing RAM dude. You need $200+US for that.
However there is one exceptiong to that:
That's $108 us so that's gotta be well under 100pounds, BUT I know newegg doesn't ship outside the US and it isn't even in stock there, but if you can find that particular RAM you will have some good RAM...keep in mind though for awesome OC's it takes a good amount of voltage to the RAM and generally keeping a fan blowing down on the sticks to keep it cool is advised