Active versus passive is how they make the 3D effect. More in http://www.3dtvtechnology.org.uk/passive-versus-active
Resolution is the number of pixels on the screen. Full HD = 1920 (horizontal) x 1080 (vertical).
So these are different things. Read the specs of the TV's you consider to see
(a) what 3D technology, and
(b) what resolution
Then choose the one you like most and can afford.
I was thinking about buying LG's Cinema 3D TV, which I heard is the same way as in the theaters. However, I also heard many people say that passive 3D is not a full HD 3D TV. Is it true, or is it just another rumor? Can you really tell the resolution difference between active and passive 3D TV?