If I had a current hungry speaker and wanted to get decent results without remortgaging the house I would get a Sunfire load invariant amp. I have never owned any Wilson's though and probably never will. I typically wouldn't go for speakers that are tough to drive unless they were panels for the exact reason that I couldn't use the amplifiers that I would want to.
Amplification for Wilson Audio Sasha on the cheap
What have you been driving your Sasha with and getting that low controlled huge bass.