I own a 50"plasma pn50b860 samsung.  I have been looking at wall mounts and reading some other posts on here.  I want one that tilts, and moves left and right.
The one that I have been considering is 
Adjustable Tilting/Swiveling Wall Mount Bracket for LCD Plasma (Max 132Lbs, 37~63inch)
The design looks sound, but the only problem that I can for see is the base that fastens to the wall.  I think it might only be 18" wide.  I can not be for sure from the specs on the page.  My studs do not seem to be exactly 16" on center.  Does anyone know of a wall mount that would work and have all the features I want for studs that are not standard?