Options to upgrade from Cambridge Integrated

Of the speakers on the short list, I think the vandies will not only have the best overall sound, but will also work best in your large room, especially if you're able to place them out in the room at least a couple of feet. I had 2ce's and ran them with a 50 wpc cambridge integrated for a while. Worked fine, though they did sound better when I moved to a 100wpc mccormack amp and tube pre. But in with your budget, you might be able to have it all. Used 2ce's go for around 400. That leaves 1000 for a more powerful integrated or used, older seperates. Congrats on the new space I bet jazz and vocals are going to sound killer, though rock may not have the punch or slam you'd want.

Nice to have the update!

Your new listening room dimensions have indeed changed the equation. You are not looking at steadily improving your present system any more, starting with speakers (the weakest element right now) and later changing the amp. This is because neither your present speakers nor your amp is well-suited to a large room. If you want to try to match your system to the new room, you will need to take a big step.

My take would be this: unless you plan to listen nearfield (and forgo the "room-filling sound" experience), you will need speakers that can move a lot of air. That means forget monitors, you need big woofers, or multiple woofers. Such speakers need muscle unless they are very efficient, and muscle costs.

Speakers with an efficiency rating under 88 dB will need a big amp, at least 150 wpc if solid-state and about half that if tubed. If you can find a speaker you like with a 90 dB rating you can cut your required amplifier power in half. That's a lot less money, and often better sound, since IME the smaller amps take less engineering and fewer exotic parts to sound good.

My first notion would be to listen to one of the Triangle floorstanders. (I would be tempted to say, the bigger the better!) These are efficient speakers with terrific imaging, very lively and fast and not terribly costly for their quality. Their sweetness depends on what's upstream of them, though, and tubes are a good bet here. Another good bet speaker-wise would be Reference 3A, but these are more costly than Triangles. There are sure to be other efficient larger speakers I can't think of right now.

Vandersteens are not the worst idea with your current amp but I agree that this setup will sound meek, even a bit lost, in your new space. However a budget revision, upwards, may not be feasible under the circumstances.

OK Tobias, you have introduced another speaker into the mix. Now I'm going to have to listen to them, darn :)
Where can I get to listen to the Triangles. Any chance there is a dealer in the Atlanta area?

I will start listening within the next week or so. I agree that the size of the room will be better served with higher efficiency speakers, especially if I want to stay in my budget, at least for now. Post any other suggested ideas and I'll update everyone on my progress.

Another vote for choosing speakers first.
I used to own B&W 603 but they weren't compatible with my ears. Now I'm happy owner of Vandersteens. Get all advice but make your ears the ultimate judge!

I'm also doing some integrated comparison tests, including the Cambridge yet since speakers seem to be the direction this post is going, my 2 cents is to suggest the new USHER S-520's for $400, there is definite WOW factor, both musically and looks. These speakers are so hot right now they are on backorder across the country. I'm trying to pair up an inexpensive system w/ these spkrs and having my own fits about all-in-one or separates. Good Luck