Casey, if you haven't already seen the post on the Water "H-Bridge" you might want to check it out. Using just three valves, you can install this device that allows you to fill your tank from the fresh-water drains and use the TMs built-in pump to suck water from a container using the city water connection (this in addition to using the pump as you normally would).
It's a bit of a pain to install but I think you have the skills. Many (including me) find it to be among the best upgrades of them all.
Check out
http://www.trailmanorowners.com/foru...t=10458&page=4. A parts list is there towards the end of the page.