The question of Cellulaze or Liposonix should never enter your mind. These are two great products, but they are designed for two totally different purposes.
Cellulaze vs. Liposonix
LipoSonix is an ultrasonic fat blaster. Liposonix ultrasound energy is focused in the subcutaneous fat layer beneath the skin, eliminating unwanted fat cells around the waist. Their slogan is "1 Treatment, 1 Hour, 1 Size Smaller". What is important to note is that this product is fat reduction not cellulite treatment. If you want thinner thighs, you might consider LipoSonix, but if your complaint is about Cellulite, you should be considering one of long term cellulite procedures like Cellulaze, VASERsmooth or CelluSmooth.