I've also been looking for this type of software, and it is very limited. I just found this one:
http://www.sketchup.com/cgi-bin/store/NCSU40NEW.html
You can get a free trial, but the application is quite expensive. I'm using some PC application that I bought for about $60, so this was a shocker.
Others I have seen (
this one, and
this one) are cheesy and/or classic only.
Not a lot out there that I've seen, and I've looked several times.