I'd be much more tempted to change the balance of your spending, and go for about £1k on a plasma and £700 on the speakers. Don't underestimate quite how much difference your speakers make - I spent £1k on speakers and £250 on the TV and I'm glad I did it that way.
I think, from what I've read and from looking around, that HDTV is probably somewhat overrated. Things like the colour, contrast and general ability are far more important than any HDTV compatibility. When you see HDTV in shops it can look stunning, but remember that not only are you looking at it from normally about 1m away, HDTV programs will be rare for quite a while. Sky HD when it comes out will probably only have a few premium channels offering HD, and probably on an extra pay-per-view basis or some such money making nonsense anyway. HD-DVD won't be around anyway for a while, and normal DVDs watched on a HDTV compatible set probably won't look much different. It might well be worth it in 2 or 3 years time, but right now, it probably isn't.
Even if you did decide to go with an HDTV compatible plasma set, I'd still consider spending some more cash on the speakers and amp. At least listen to some more expensive separates setups before you decide to buy the cheaper ones - I'd be amazed if having done that you thought it wasn't worth spending the extra.
FWIW I'd look into
this or
this amp with
these speakers.
HTH.