Then the next step up is a 1200 W amp with speakers that weigh 100 pounds.
The 1200 actually has two 600W output sections, so you sort of already have what you want, except you get a spare output section. Also the amp weighs 11.5 lbs. Maybe your just being hyperbolic with "100 pounds."
AFAIK the ELF has been a decent seller. I don't get the idea that the 1200 is doing as well. Not many people seem to be talking about it AFAIK.
I believe the features selected for the 1200 were a differentiation strategy that hoped to rely on economy of scale. Economy of scale means if you make more of something the cost per unit goes down. By giving the amp more power and still selling it relatively cheap they hoped it would be a big success, allowing them to get a good return on a smaller profit margin. Sometimes strategies work and sometimes they don't.
AFAIK none of the amps introduced with dual output sections have been big sellers over recent years...or perhaps ever. This format is most advantageous for large touring rigs where you need to push a bunch of cabs. My perception is the touring industry is changing and is not longer driving the features in top of the line bass gear in they way it used to. The new TE cabs also seem to be tailored more for touring use as they are fairly large and heavy by today's standards. The probably sound great, but I doubt they will be big sellers.
The street price for the 1200 is $999; the same as a Mesa D800. If 1200 only had one output section, my guess is it probably would have to sell for $800 to $850. It would also
mean the 600 would cannibalize sales from the 1200. This could push the street price of the 1200 up to something like $1049 or $1099, which might be reflected in a higher price for the 600 as well. Unfortunately when you make multiple products, it can result in higher prices for all of the products.
Although I am pulling these numbers out of my butt...this is actually how this sort of stuff works.
Although it would be cool if Peavey could offer a Trace Elliot 600...I doubt they will as it simply is unlikely to be profitable.
Good luck!