Well, here's a picture of the new kit that has been purchased and now racked in the last week or so.
Denon DN-X500 replaced with Pioneer DJM3000.
USB sound card and GLI removed and replaced with Denon HC4500.
I was awaiting news that the HC4500 is now mapped in native mode for Virtual DJ and it works very well.
I've been testing it with just one of the new RCF cabs and I don't think I've ever had a system that is so quiet when nothing is playing. I've always had a slight mains buzz or hiss through the horns, but this is silent. Nothing.
I'm impressed with the sound so far, but then I've only had a play in the garage and front room!
As you can see the case is wasting a lot of space as there are no CD draws, only a 1U keyboard sliding shelf and the Pioneer mixer is quite heavy, so Steve is buiilding me a bespoke case, out of lighter material, so that everything fits and there's no wasted space.