I've done my research and I'll tell you what I know, it will be up to you to find the best deal because it depends on what is important to you. I would, however, spend my money on a reputable brand at a reputable location.... otherwise expect to run into problems, and expect to have a hard time solving them.
Plasma screens are not as bright as LCD screens, and many people make the decision between the two based on the amount of natural light in the room they will be putting the TV. We have 6 large windows in our room, so I went with LCD. The LCD's usually have a slightly better viewing angle too, but the Plasmas have a better contrast ratio (blacker blacks... resulting in whiter looking whites) You will usually see the plasma ratios around at least 30,000:1.
A 1080p TV is great to have, and you can get one very cheap now compared to what they used to be... however, it's not necessary unless you plan on buying a blu-ray player. Even when HD broadcasting is in 1080p, a 720p will still work great. The number 720 and 1080 have to do with the number of horizontal pixels, so sometimes you will see "1920x1080" which gives the vertical pixels too. The "P" means progressive scan, and if you see 1080i, the "I" means interfaced. I don't think it's gonna mean a thing for me to go into that... progressive is the most capable of the two, and much better for sports. I always keep my TV on 720p instead of 1080i for this reason. Hope this has been helpful. Don't forget about the money you will have to spend on an HDMI cable (one for tv and one for every compatible HD component) and the service.