With so many providers to choose from lets use common sense. As an antithetical piece of advice choose a provider that actually offers other procedures as well. This way via common sense they will offer whichever technology makes the most sense for you.
For example Thermage is only radio frequency at a much higher temperature. Some providers offer both and some providers will combine both. I would also stick with providers that have at least 15 years of experience in the non surgical world with radio frequency. There are a lot of adjustments that can be made to improve your treatment and get the best results.