I searched forever and finally settled on Home Designer by Chief Architect. It's really inexpensive too.
HD doesn't run natively but I've managed to make it work both with Crossover as well as in a VM. It really is hands-down the best software for the job, it's just a shame they don't have an OSX version.
The GF and I completely laid-out our new place and it was so easy it was actually fun!