i defo think the nsk-4000 is about the best youll find for your needs and at £50 it is pretty good, its actually got me interested as m thinking of reducing my case size slightly
the only other 2 i can think of would be the antec 300 which is quite big and the nzxt source elite 210 at just 40 quid http://www.ebuyer.com/278067-nzxt-source-210-elite-white-case-nzxts210e002 white http://www.ebuyer.com/278066-nzxt-source-210-elite-black-case-nzxts210e001 black http://www.nzxt.com/new/products/classic_series/source_210_elite the nzxt is quite decent and clean plus 3 external 5.25" bays and no 3.5" external bays and although its not overly tall or wide, it is almost 50cm deep
They are definitely contenders, just for the price alone. I have actually got another build for a friend in France,who is trying to keep the costs down until he can spend a decent amount later this year so I had been looking for a case which was cheap but not a piece of crap. This could just fit the bill. So I might just get it for him which will give me the opportunity to assess it and see if it suites me. Thanks a lot for that, appreciated.