Water tank

I'm planning our first teardrop and would like to install a fresh water tank and on-demand pump to a conventional faucet and small sink, rather than use a Coleman insulated tank/cask. I've found pumps at Camping World (and I imagine I'll find similar gear at a boating supply), but I haven't found fresh water tanks yet.
Since I'm just starting, my questions runneth over:
Since I'm just starting, my questions runneth over:
- * Any recommendations on tank suppliers?
* What would be a good size of tank for, say, a weekend trip?
* Any recommendations on tank shape and/or placement?
* With shore water available, is one consigned to just fill the tank and use the pump, or is there a widget to allow one to plug the hose in and use the shore water directly?
* What recommendations do you have for dealing with the grey water? (built-in grey water tank? drain hose to a towable "blue" tank? drain hose to a bucket? drain hose to a muddy puddle underfoot? quantum black hole disposer?)