Here's £1000 to spend

PMC DB1i

Dynaudio Excite X16s.

Or sell all your current kit and buy a pair of AVI ADM9Ts, the new models are £1250 so you'd be saving quite a bit of money.

Sell the Roksan, Audiolab and Quad and buy a pair of AVI ADM 9T red dot.  Superb sound and a few quid left in your pocket.  Job done.

Towers or Monitors?

If you are trading in/selling your Quad's then you could look at the PMC Twenty:21 presuming you are sticking with a monitor.

Personally, part of enjoying Hifi and music is being able to change components. If you join the cult of AVI Adm9, that's it, it's all over. I am sure these avi speakers are good, but you will be joining the choir of voices that tell everyone to sell there kit, which sounds a bit dull to me.

I just bought a pair of used Kef q300's which have replaced my PMC GB1i's and I love the different sound, so get on ebay/gumtree and take a gamble. As long as you buy the right model/manufacturer you can always sell on and get your money back.

There are allot of fans of the AVI but I have to agree with Sonofsun - I enjoy the upgrading and tinkering.

On a serious point - I am looking to replace the Quads but what with - I was hoping you could make some suggestions that would suit the Roksan amp.

Whats the bestI could get by spending upto £1000 on speakers - I enjoy a detailed, smooth, expansive sound stage with a decent low end.

Very happy with my DC6T signatures, even better was they came direct from Tannoy as factory clearance items at half price - they sell clearance stuff on that auction site . Bargains can be found! 

Now I've just found the Kef R300 in white... it'd be them.

Sonus Faber Toy Tower (may need to be ex-dem)

Opera Grand Mezzo (may need to be ex-dem)

Spendor A3 (may need to be ex-dem)

Sorry, all my suggestions are a little outside budget, but should be worth looking out for, if on sale.

+1 you will not regret.

How about:

KEF r100
MA RX1
Roksan K2
ATC SCM 11
EPOS Epic 5

Does anyone own or have heard these in action - what are your impressions?

Whether these are suitable depends on your personal definition of "smooth". The three I listed above would be smoother, though the Epos is great and so is the Kef. The ATC will be honest and neutral. 

You need to hear this for yourself on the end of your kit.

Your desire for a decent low end rules out the AVI ADM9T's - which are over budget anyway and which will depreciate if you buy them new.

From a quick scan of UK eBay I'd go for the Canton CT 1000's for £450 if I had your system and wanted a detailed, smooth, expansive sound stage and a decent low end.

Other candidates include the Magnepan 2.6r's, Apogee Centaurs, Quad ESL 63's. In order to get a decent low end, dipoles like the Quads would require a suitable room to stop the rear firing bass energy bouncing off the back wall and cancelling the front firing bass.

Another eBay scan in a weeks time will throw up a different set of speakers that I'd be interested in if I had your system.

If your budget is £1000 including stands and cable ect then i would go with the Kef R100's with some partington super dreadnoughts and some chord epic speaker cable...if you want more bass and have the room to house them i would also recommend the R300's, for me i found the R100's to have more agility and quite frankly better in my size room 15ft x 13ft.

both are amazing speakers and can compete with speakers double there price!

as always demo with the kit you already have to get a real sence of what they are going to sound like in your listening enviroment, this is where a good dealer comes in to play..