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.
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.