Hi David.
Not sure what the current conversion rate is, but I think 1000pounds = US $1500. Not?
At the end of 2008, Dali increased the list price on the Ikon6 from $1750 to $1900. Last August, I bought a pair of new, open-box Ikon6s here on AGon for $800. That was a steal. List on the B&W 683s is $1500.
When I first got the Dali Ikons I had them in my home theater driven by an Onkyo 805 avr which is a direct competitor to the Yammy 1900 (both 130w x 7). The Ikons sounded great, but I thought they could use more power for CD stereo play. I have since moved the Ikons into my PC sourced sytem and am driving them with a 200w x 2 Aragon amp. Big difference - more drive - like what you thought the 683s had over the Ikons.
Anyways, I love the sound of B&W speakers(the rear speakers in my 7.2 home theater are the tiny LM1s - but they don't sound tiny!) My choice with the the Yammy 1900 would be the 683s becuase I think they will drive better at 130w than the Ikons would.
However, I think the Ikons driven by at least 200w will beat the 683 for stereo music. Especially with a decent subwoofer to cover below the the Ikon's 37Hz FR. Note the 683s would also need a sub as they go dowm to only 38Hz.For stereo music, I'm gonna want a sub (or 2) that has a fast response speaker and goes down to at least 28Hz. You could add a 200w - 300w stereo amp by using the Yammy as a preamp and let the Yammy drive the center and the surrounds. Something like the high value Emotiva amps which seem to be all the rage now for supplemntary power in home theater systems.
Besides the Ikon6 and the 683, you might try to audition any of the following speakers:
> Revel Concerta F12
> Monitor Audio Silver RS6
> Aperion Audio Intimus 533-T
> JBL Studio L880
> KEF iQ9
> Silverline Audio Prelude
> Almarro M0A
> Polk RTi A9
> PSB Image T65
> Tannoy Eyris DC3
> Totem STTAF or ARRO
Bear in mind that if you are using a center channel speaker, you will want to match as closely as possible its timbre w/ that of your front left and right.