You could have a look at coolermaster cases they are really good when it comes to space for water cooling (some have pre cut holes at the back for the pipes) etc. and they are well constructed.
The HAF 932 is just about in your budget (quick search showed £103 inc. del ) HAF 932
But if you save a bit (around 130 squid) you could have a look at the COSMOS S
I've got this case and it is just brilliant (tons of room inside) --- worth every penny COSMOS S