I'll throw a few more pence in the bucket...
If you just want to plink at home then a pistol is a good choice as its more fun to use than an Electric weapon (AEG)
As Tommikka said, you could just buy a two tone coloured pistol without any legal requirements (as long as you're over 18)
But I would also recommend to try renting at a game site to see the true potential of the sport. If you don't like it then its not a big cost and you will get to see lots of weapon options. (I preferred woodland games with sneaking around and a range of weapons but indoor CQB is faster and can be played just with a pistol)
If you do like it then you'll only need to attend two more games at the same place to register with UKARA and then you can buy any realistic coloured toy (RIF)
Check HERE for sites near you.
Either way, have fun ππ