Regarding water cooling etc. Is the one selected ok or too much? Also should I downgrade the case and up the speakers?Any other tips?
Its not too much as you have a overclocked i5 2500K.
As for the case, these are good options from the list,
Silverstone SST-RV03B-W Raven 3 Windowed Case - [add £70.83]
Corsair Obsidian 650D Gaming Midi-Tower - Black - [add £75.00]