Letters of recommendation

[wb3060]

I am applying to switch PhD programs upon completion of my master's this year (current PhD student). My first letter will be from a professor I have been a research assistant for since starting the program (with very close research interests to my own). At the end of spring semester he left to work in another (more highly ranked) department. My second letter will be from a professor in my subfield who I've taken two classes with (in the second now). I need advice on the third. I could have one from someone at a much higher ranked department than my own who I've done some RA work for, or I could ask another professor in my department (who could  vouch for my methods abilities, but so will my grades in those classes). I'm worried that it will look like I don't have support in my department if only one of my letters is from a professor currently in that department. I'm not sure if the one who left will "count" in that sense. Thoughts?

Edited September 25, 2015 by wb3060