Well she's ok now and won't be getting struck by a smooth criminal ever again or whatever happened in her past life. Good on you!
That seems more common in Canada, and elsewhere in the U.S. No basements in Texas. Some people have mother in law houses or a second/third story attic conversions for rent though around universities and urban areas.
Don't buy a brand new orange to turn it into something it's not.
I'm willing to bet you have a friend or musical acquaintance with an SVT, or maybe even a v4 to try. If not I've never been to a guitar center in my life that didn't have an svt 810 stack with a massive price tag standing proudly at the center of the bass nook.
I think ampegfuzz is right you could get away with using a v4, but a v4 preamp isn't an svt preamp in a lighter package. It's a baxandal but different frequencies are attenuated by the controls. At least in the old ones. That said if you love the Early Ewiz tone the most and know he uses a pretty basic svt rig and muff, I wouldn't stray far from that. Why spend more on an orange, then spend more turning it into something else to cop a tone he didn't have. Svt you know you'll have the power and the tone you hear on most records from country to doom at your disposal.
Also I don't know why you have to do
sweetwater exactly, but if it's just for the layaway go look at pawn shops too. I bet one might have an svt or other cool head.