Iago, Bart,J's approach is probably the best. HOWEVER,There are a couple of other options for your install.
\Hire a commercial contrator to install a 1/2" steel wall plate to the
entire wall you are installing your new pasma tv on. This is much more secure than the wood mounting options discussed earlier. They could fasten this new substrate using 20 or up to 500 mounting points. The tv will be secured to a solid steel wall and will never come down (unless you use your deck screws to mount it to the wall). Or there's an other option< the one I prefer when mounting to 24" studs. First, return your 16" Omnimount Call your loca,l A/v custom installer. Ask them if they carry SANUS TV wall mounts?
Sanus has articulating wall mounts for 24" stuud pattern's. ( nice & SIMPLE).\
Articulating mounts from SANUS can hold up to 175lbs. Extend up to 25" . Check it out. www.sanus.com. By' Guy's. I Think it"s going to start Snowing next week.(Lake Tahoe), HAPPy HalloWWeEEn, BC