I found a pretty neat compatibility site

[guidedbyechoes]

http://www.marinecompatibilityguide.com/compatibility

Basically you enter two fish and it gives a rough estimate if they will work or not. It also works for certain inverts.

 

[guidedbyechoes]

This is the pending stocklist for the 180 I want to build
http://www.marinecompatibilityguide.com/tank/30f124be?an=7&ca=12&re=7&co=7&te=6