We had a similar dilema, i am a rock chick, H2B is an indie kid! In the end we went for a band that does a combination of a few 60s classics (Beatles, Rolling stones etc) to keep the oldies happy, then they will do a more rocky / indie set for us to appreciate and finish with more party songs such as summer of 69, a bit of queen etc.
In between sets we are going for ipod cheese!
It will either be something for everyone, or just wont gel, but the more people drink, the more open they after to dancing to anything!