Asking which machine is best for this is like asking which Ferrari is best in the hands of an eight year old. Even the best machine can lead to absolutely disastrous consequences if placed in the hands of an unskilled and unworthy physician.
The problem even becomes more compounded when you put a powerful laser in the hands of a newly minted 'cosmetic surgeon' whose only qualifications were the ability to pay the requisite money to purchase it.
To answer your question, however, there are more powerful lasers made by the company that makes SmartLipo. The problem is that the possible complications only get more concerning as the power of the machine goes up. Additionally, the rewards don't generally improve much as the power goes up, because the thing that aspirates the fat isn't the laser, but the method being used to remove the fat and the skill/attention of the surgeon.
You need to be focusing on what method and training the surgeon has as that is going to be the thing that will determine if your procedure is successful, NOT the laser! Additionally, you should be looking for someone who performs tumescent liposuction as that is very important and allows for the least amount of risk with the greatest amount of benefit. Good luck!