We'll you can plumb the R/O from the bathroom like you said and have it go straight to a float valve for AT. If you think about it, your only going to be doing water changes every couple weeks so hauling water won't be the end of the world. Especially if you have a already have a water carrier supply your office with water jugs for the dispensers. You can just take a couple into your office.
I am going to get a bench-like piece of furniture i can put next to the tank and custom make, hopefully a 15 gallon container to house my Water for top off.
As for as the tank... I would say go rimless! Mine was a little loud at first because of the waves going into the overflow. But i added a sponge filter to quite that down. Other than that, they nice for feeding, WC's, Adding/moving rock ect. I love not having a canopy to open anymore.