The deal with Acoustic is: they existed as their own brand in the 70's and 80's, then went out of business. Guitar Center bought the rights to the name and "trade dress" (looks and basic functions) of Acoustic, and started having budget versions made in China. Another independent fellow decided to make a high-end version here in the US, but his legal wranglings with GC, and countless other hurdles, have kept his product from actually entering the market so far.
So look on Ebay and the TB classifieds if you want a vintage Acoustic, they
do show up with some regularity. If you wanted the new made-in-the-USA high end ones, you'll have to wait a while longer--in fact, nobody knows how long.
Aside from that, there are lots of great options these days. A used Carvin B1500 will bring ultra heaviness for not much coin. If you want the sound of a beefy solid-state amp being driven quite hard, check out the Tronographic Rusty Box preamp--there's one in the TB classifieds--it was designed to emulate the hard-driven solid state amp used by Shellac. Run it into any decent power amp.
For cabs, there are a zillion options, but the general rule of thumb I'd use is: more speakers = more heavy. The more speaker surface area you have, the more doom you will be able to pump through them without ripping up the cones. A popular doom choice is two 8x10's.
