There is no reason to get a 120hz+ LCD TV, it is a gimmick that is only really good for sports or video games. It makes normal TV shows look "fake", with actors moving like they are animated. Very weird. Apparently some people don't notice it (how I have no idea) but that's that. Good news is you can turn off 120hz (or 240hz) but don't take it as a "feature" worth having.
Best advice for you? Go to cnet.com and read their TV section. Plasma's are still to this day the best for picture quality and black levels, but are not appropriate in a room without controlled light. Also note that there are two different types of LED tv's (edge lit and back lit). Back lit = win, but they get pricey quick.
In Canada, I can get a good quality 60" for under $1500. You should be able to find a 55" for a grand down in the US. Be aware that 55" is an odd panel size, 50s and 60s are much more common. I would personally downsize the tv (50") to get a better quality TV, as a 50" tv viewing distance is still 10+ feet (most people don't have that kind of space).
One thing to also remember, you should get the tv calibrated. DIY or professional, it WILL make a difference. ALSO ALSO, if you are unhappy with the TV, friekin' return it. There aren't many things you spend a grand on, and that is why there are 30 day return policies. It is extremely hard to compare tv's at stores (they give poor quality feeds to tv's with low margins and high quality feeds to tv's they want to sell, lighting is bad, etc etc).