Just add sistered 2 X's to the side of the floor joist to bring it down below the plumbing. 2 X 6' floor joist are way to narrow for anything more then a 6' run, and way to narrow for a bathroom, so adding more support would be a good thing.
You do know there's about 100 differant styles of dropped ceiling panels avalible that you could just drop in place to make it look better and less work.
Check out a company called Outwater.com.
Last edited by joecaption; 11-04-2011 at 06:57 AM.