Plasma screens are best for more dedicated home theater arrangements. Their black levels and high contrast ratios are great for lower levels of ambient light and having no direct light sources such as sun coming in a window. Issues with burning images into the screen are possible but are less likely after a few hundred hours use.
LCD screens are a better all purpose choice for viewing in rooms where overhead lights will be on, windows open, et cetera. This is because LCD's tend to be brighter overall. Their picture quality is not as good as plasma but the gap is quickly narrowing.
Pick whichever best suits you and your watching environment.tastes.
Also, as far as HDMI cables go, here's the best test I've seen. They used signal generators and test equipment to determine that, so long as the cable is capable of getting the signal from the source to the TV, there is no difference between cables.
http://www.pcworld.com/article/12177...able_game.html