Fantastic, thanks for that.
And sorry, yep... I'm in the UK and didn't have a particular budget in mind. Something compact was my main concern. The tube pad seems like it might do the trick. I'll have a look at what's around in the UK.
Thanks again for such a quick and helpful reply!
Incidentally, the 522K comes with a hit-hat pad and two cymbal pads (a crash and a ride). If I wanted to add another crash cymbal, are there any particular models of pads which might be recommended as an expansion for the 522K, or just another of the PCY100 pads?
Finally if anyone knows which input I might want the y-splitters on - so the extra pads default to a cowbell and an extra cymbal on the default kits without having to create custom kits for each one - that would be super-handy!