using something akin to the rubberized exhaust hangers for your tank. Still a strap or tray mount, but suspended such that frame flex is a non-issue. But that is counterintuitive to off-road driving, washboarded roads etc. And a full gas tank weighs a hell of a lot more than an exhaust system. Or configure a tank that runs predominantly in a crosswise direction to frame twist is less of an issue, or two smaller tanks side by side independently mounted, either plumbing both fully or using one as a transfer tank.
As for the 'granite' lol, there's lots of attractive laminates available now, or even a 1/2" thick Corian(?) counter that will give you 90% the look of granite at far less than granite weight. Use 1/4" alum plate veneered with laminate. Rigid enough, weighing a tenth? of stone. Think 'veneers' for just about everything. Thin and light, you can have as 'rich' an interior as you want for little weight and lost interior room, and at a moderate cost. I'd be happy to mail you a couple of my scrap bits of the PSA Oak veneer I refinished my kitchen cabinets with, for your inspection / consideration. The stuff is about 1/16" thick and took stain and finishing like a champ and is stuck on like krazy glue.
(I made the 35 cab door and drawer fronts from scratch too, took a while later to get it all done)
Anyway, my point is you can do a lot with veneers and have it look real nice.
How's your overall layout coming, have any overall pics or finalized design sketches? I've lost my grasp of your overall layout. You still wall-mounting things and having them fold down into place for use? IIRC you mentioned bike stowage? can the bike hang from teh ceiling without impeding other things? What's your shower / sanitary setup, gray / waste tanks? small ones?
