recommend me a flash?

I need a flash powerful enough to blast away all the crappy household lighting in my living room. It's not a matter of insufficient light, but bad light (some non-flash uncorrected photos have a "puke cast"... LOL).

I use an SB-700 on the Nikon D7000 DSLR at 1/250 to 1/500s with excellent results. But after a while my hands get cramped from holding 4 lbs of gear, so I need to mix it up with some non-flash and some external remote flash.

What would you recommend for use with an E-PM2 for similar results to the D7000/SB700 combo for on-camera bounce flash?

Thanks