Home Theater Fronts, Center & Receiver - 2K Used

I'd go with the KEF/Arcam setup, should sound great...

-RW-

I'd probably find some older good sounding used B&W center channels n use three of those across the front, set on end, a-la THX style (must mind room acoustics issues n treatments without using horn speakers or focused sound propegation directed speakers...or recommend long wall setup, minimum), then some small matching series minis in back. ..keep ur sub if u like it. Then maybe consider a nice anthem AV receiver w room EQ (you'll most definitely need that, BTW).
Otherwise, go similar route with other brands u like, but I recommend at least twin mid\woof DAppolito configured speaks for solid sound propegation , power handling, dynamics, n lack o distortion, up front. (I only recommend single woof\tweeter music speakers in small room spaces)

As a budget minded person, I think you definitely have to take a serious look at the Anthem MRX series. You can even use a separate amp or even a good stereo integrated to drive the 2 front channels. The Anthem has one of the best room correction system on the market and it comes with the microphone, mic stand and software. If you enjoy movies or concerts (on blurays) you will love this system.

I shopped all over to find a amp/preamp combo that would give me the best of both worlds at a reasonable price(yes I am also and audiophile) and I recently bought the Anthem MRX 510 and a Hegel H80 (which drives the front channels, it has a home theater by-pass). I defy anyone to find a better overall solution for all my needs at less than $4,000 (Amp/ pre amp).

If you have smaller acoustic space in, say, a modest smaller flat, I'd say you'd probably do good with some acoustics friendly Kef UniQ driver, coaxial, something'er-other's, matching center and or surrounds, and stay with your favorite British amplification, integrated, etc. Then, as you say regarding the lack of UK based Surround soundy gear, I recommend you loop a good HT digital processor for Dolby/DTS Master surround, into your two ch pre and or multi-channel amp setup, and look for budget. What comes to mind, is something like Emotiva $699US prepro, with EQ. Probably do plenty for your movie application, and then you switch it out of the loop for your 2 ch British sound duties.
Pretty sure you'd be happy this way. Peace...