Did a lot of research recently so I can give you some pointers.
Don't get anything less than 720p
Get one with a built in HD tuner
I got mine from Amazon.com with free shipping (Eagle shipping brought it, set it up, and made sure it worked before leaving) with a 4 year warranty for less than anywhere in Ft. Lauderdale for just the TV.
A Geeksquad / Firedog install will cost you big $$, install it yourself
You can get HD channels from a regular cable package offering
You can get HD channels over the air with a regular attenna
There's no such thing as an HD antenna
Good luck!
