Power draw depends on your choice of brightness. These are from around 8 years ago for a 32" Samsung LED LCD whatever it is:
Movie- 70w, Standard- 80W, Dynamic-120w
A 32" LG about the same age had:
Intelligent sensor (varies with room light) 65-25w
Vivid- 70w, Standard-50w, Cinema-35w, Sport-65w, Game-45w
Those TVs are heavy compared with new 32" flat screens and I don't have wattages for newer ones.
The new ones have legs for stands instead of a pedestal and they hang the remote sensor underneath so you must have clearance for that sensor. No problem up on the arm. The leg screws after you take the legs off can be used for the backing plate on the arm if you are lucky. Some have different size screws for the four hanging up screws than for the legs, so you might have to dig into your junk drawer for the four screws that go in the back.