Alex - I got the Samsung PN64D7000 - It's a plasma, not an LCD.
In this situation, with the type of viewing, and going from a DLP setup, I would think that plasma is ideal.
I would be interested to know what the original poster believes that LED backlit LCD is the way to go?
For about $2,500 you can get the 64" Samsung D8000 series plasma...
Amazon.com: Samsung 1080p 3D Plasma HDTV: Electronics
A few hundred less for the 7000 series which I purchased.
I do like Samsung LED lit LCD displays a lot.
It's about $1,300 MORE than the D8000 series plasma for the 65" D8000 series LCD...
http://www.amazon.com/Samsung-UN65D8000-65-Inch-1080p-Silver/dp/B004Y45RXI/ref=sr_1_3?s=electronics&ie=UTF8&qid=1321593372&sr=1-3
That's a huge jump in price for what actually amounts to a reduction in quality.
Also worth saying: Get a Blu-ray player!
3D hardly matters, but you can pick up a BD player for under $100! Why don't you already own one if you want great quality?
The only reason not to get a plasma is if you do a ton of gaming on it and may possible get burn-in, which you didn't indicate.
Or, if you have a ton of windows in the room and need a lot of additional brightness. Since you've been using a DLP rear projection setup, I fully believe that you do not have serious lighting issues in that room.
There is also the Sharp LED LCD displays, but they simply don't look as good as the Samsung displays.
Panasonic also makes some great plasma displays that are 65".
They run from about $2,000 to $3,000.
Amazon.com: panasonic 65 plasma: Electronics