Francois, just like to add my little tid bit. IMHO Any sales team needs to be managed rather than rewarded only, with that I mean that they often end up managing perception and try to meet their deadlines at the last possible moment.
I have a serious suggestion that regardless of their basic and commission you should set them daily, weekly and monthly targets. Knowing your job is on the line can be much more effective. However there is a balance that needs to be found. It is crucial that your sales team are motivated instead of threatened by these targets.

In my opinion, regular training and attitude guidance is a must as well. Keeping the sales team motivated can easily double your profits and make those training sessions absolutely worth while.

Also ensure that you set targets that are achievable but still challenging. From a target point of view you must always aim higher than is really required. Many salesman only aim at meeting their target, and when the slightest thing goes wrong, the targets are not reached and they are full of excuses that even they believe. If it is possible raise the bar regularly to keep them on the ball.