Just be careful of weight limits if you are buying a swing arm or similar type. I found when looking for one for a 50" a couple of years back that some of them weren't suitable for heavy plasma tellys despite being advertised as for 60" tv's. It wasn't hard to find a suitable one though.
Buy Kanto Living PDX680 Full-Motion Wall Mount for 39 to 80" Displays (Black) featuring Supports 39 to 80" Displays up to 125 lb, 200 x 100 to 700 x 400mm Mount Pattern, -3 to 15° of Tilt Adjustment, Up to 170° of Swivel Adjustment, Adjustable Horizontal Leveling. Review Kanto Living PDX680
Looking at the bit that fixes to the TV I can't see how you could have any problem with it fitting. I'm assuming you are in the US but you could use the bracket finder in the link below to see what alternatives there are then shop around for better prices.
I need your help with something different. I put the wrong size screw in the pedestal with the TV on and I stripped the screw. Can't unscrew it and can't turn it. Do you have any ideas what I could do?