The one thing I don't see in your equipments list is a AMP. There are many fine speakers under £400(per pair?), if fact you can do well for even less.
But keep in mind, that your TV probably has a roughly 5w to 10watt amp, and that limits the speakers you can drive. What I am referring to is the fact that may speakers have a minimum recommended power rating. They typically need 15 to 20watt to work effectively.
At the top of the page for this and all the other forums here, you will find a section called "Today's Offers". One of these listed items has 6 offer, select that one, as you don't care what they are offerring, you only want the list of 6 on-line resellers. Notice on the right hand side of the next page, you will see 'Star' ratings for the various resellers.
SuperFi seems to have a reasonable selection to browse. Look there at speakers that appeal to you, then click on the speakers and look at the specs, if you can find a speaker in your price range that DOES NOT have a minimum power rating then you are good to go.
Personally, I recommend at least connecting the outputs of the TV to a stereo amp. More preferably if TV and Movies are your biggest interest, invest in a good A/V amp and connect to it. Of course then, you are going to want a 5.1 surround sound system, although 2.1 (two fronts +Sub) and 3.1 (two fronts, center, & sub) are also possible.
Complete 5.1 surround packages can be had for your price range -
Take this examples -
WHARFEDALE DIAMOND 9 HCP HOME CINEMA SPEAKER SYSTEM (£330)
http://www.superfi.co.uk/index.cfm/page/moreinfo.cfm/Product_ID/2210
If you can give us a clear indication of what equipment you have, and what you have in mind for the £400 you plan to spend, we can probably make better recommendations. For example, do you have an existing amp; stereo or A/V 5.1/7.1? Are you looking for a pair of stereo speakers, or are you thinking of a surround sound system? Floor standing speakers or compact bookshelf speakers?
£400 will buy you a VERY nice pair of speakers, or a good midrange 5.1 system.
If you are looking for a pair of speakers, you can get them for much less than your budget and have money left over to pay for an amp.
Here are a few very nice pairs of speaker for much less than your budget, they are copied from another discussion in this group.
Wharfedale Diamond 9 ( £89/pair)
http://www.superfi.co.uk/index.cfm/p...roduct_ID/2196
Warfedale Diamond 9.1 ( £129/pair)
http://www.superfi.co.uk/index.cfm/p...roduct_ID/2197
Q Acoustic 1010 ( £89/pair)
http://www.superfi.co.uk/index.cfm/p...roduct_ID/2842
All Award winning speakers.
Does that help at all?
Steve/BlueWizard