I am wondering if I should try ultrasonic cavitation, laser liposuction, or do I need actual liposuction? (photos)

I believe I've tried most approaches to liposuction. I've settled upon conventional liposuction assisted mechanically. I would focus more upon the surgeon in the results rather than a specific technique. The best technique in the hands of the lousy surgeon is going to leave the poor result.

All types of liposuction can obtain good results.  Its really more about the surgeon and his/her experience with each type. There is not one type that is always superior.   But I do like ultrasound lipo for re-do cases or in areas that have more fibrous tissue.  Their may also be slighter more skin tightening with ultrasound.  That being said, the posterior thighs is not a good area for liposuction and I would be likely recommend that you not have it done in that area.  Contour irregularities could easily occur.  Make sure you discuss with your surgeon.  

Liposuction and Techniques -- SmartLipo Versus VASER Versus Traditional Versus WAL Versus ThermiRFIt is not really the tool it is the technique used that gives the results of liposuction. You want to find someone who is an expert in the field and has a practice dedicated to body contouring/liposculpting. A formal assessment is needed to determine which techniques are best, often I am using 2-3 devices to get the most fat removal, skin tightening, and contouring. Also, I am often transferring fat to other areas to get better shape and long term contouring. I suggest a consult with a liposuction expert. Best, Dr. Emer.

Your question is great as it brings up some really important  issues in considering liposuction.The ideal patient for liposuction is one who is not overweight but has localized area of excess fat such as the most common area the outer thighs.  I don't see localized areas of excess fat but a general layer over the entire thigh area.  Liposuction in your case could leave you with indentations and irregularities in  contour. So my recommendation would be weight loss.Here is what I recommend for weight and life style changes.1). Always eat breakfast and do it within 1/2 hour of waking up.
This jump starts your metabolic furnace and so you "run" at a higher level
throughout the day burning more calories. I have an egg, 100% wheat toast and
steam flashed spinach or any other high anti oxidant food.
Steam flashing in a covered pan with a small amount of water unlocks the antioxidants.2). Never
eat after 7 PM. These calories are not burned and are converted for deep
storage (fat).
3). Eat vegetables in place of complex carbohydrates. The
amount of energy in carbs is very high so avoid sweets, breads, pastas, and chips,
crackers.. Replace with broccoli, spinach, etc.
4). Do not consume diet foods
or drinks. The artificial sweeteners (aspartame,sucralose,saccharin) are worse than sugar, they cause insulin
resistance causing a profound effect on sugar levels with conversion to
fat. This is not widely known but it will be as studies are supported
this.
Use Stevia (often times with erythritol), a natural sweetener instead.5). Take a brisk walk or do something active for the 15 minutes after
each meal.
6). It's a simple equation: What you are = What you eat - What
you do. In this equation the most important is what you eat. It is much easier
not to eat that 500 calorie piece of cake than to try and burn it (about one
and a half hour of hard working out for most).  Exercise is important for cardiovascular and bone health, but how many people have you seen at the gym who seem to remain overweight despite working out all the time.7). You will be hungry when loosing
weight. Learn to enjoy being hungry knowing that you are burning your own
sugars and fats.
Notice how these are lifestyle changes, not some new fad diet.  If you are struggling with what to eat, I would  recommend looking into the Mediterranean type foods.  If you follow  through, you will look and feel so much better!

Thank you for your photographs and questions.  Though nothing replaced an in-person examination of your skin quality, and a thorough discussion of your results, you look to be an excellent candidate for traditional liposuction and if a little skin tightening is needed, then ultrasound liposuction.  Hope this helps