Rhododendrons: Matching Rhodos

Hello all, in case anyone has these in a grouping, I could use some advice.

I am thinking of pairing Canadian Sunset (5') with Seaview Sunset in front (2').

I would like to add to them one more specimen, something larger than 2' but not necessarily larger than 5' at maturity, in a mostly solid colour that would match the darker pink/plum tones in the other two rhododendrons.

Has anyone got any recommendations?

 

Be sure that they will have flowers at the same (or overlapping) time.

 

Ack...it gets complicated, non?!