Modified black water tank

[Marlboro Mafia]

Just bought a '61 Safari.

Anyone ever install an above floor black water tank that would replace the small one under the toilet and the run under the vanity and into the closet on the other side? Would this work?

I have a twin model so there is a huge metal water tank in the driver's side under the bed. Could I add a gray water tank under the other side bed and somehow pump the shower water into this tank? Nothing large, just enough for a couple of days camping.

Thanks for your advice!