We tried this on two occasions. It can take a year to develop good contacts for big ticket productions, so the commission only guys did not last long enough to develop those projects.
It really depends upon your market.
You may consider hiring a producer with sales or marketing experience who can take his or her sales through production.
I first started out of college as a salesman for a post-production company. I was paid a base salary that was just enough to live on plus a percentage of net sales for new accounts only (I think it was 20% net). The position also included health insurance. Like Mike says, it takes a long time to create good contacts for big ticket sales, and for the most part, many newbies are not very skilled at it.