There are rules of thumb out there as Lam offered. But ya gotta know my friend that those rules are for normal people. You do not qualify as normal Max. I had a 62" I watched from 7' away and loved it. Like being at the theater.
Plasma's are not long for this earth. With a plasma each pixel is gas charged. When that positive gas charge equalizes with its environment, as it will constantly attempt to do, you get a single dark dot where that dead pixel should be ... times the number of failed pixels. The warranty on any plasma requires you to accept several dead pixels before they replace the unit. The warranty is short for a reason. Expect no more than 5 years out of your plasma TV before you see many dead pixels.
LCD and DLP are the next gen. DLP has been well-received in the home theater world primarily due to two video quality advantages - better contrast and the lack of pixelation. Blacks are solid and well ... black while LCD's have had a more washed out dark color pallet. Todays LCD's are better but DLP's still kicks ass. One benefit of LCD is that it controls red, green, and blue independently through three separate LCD panels. You have better control over color adjustment allowing you to change things to suit your own eyesight. Since you can see the colors like magenta and fuchsia better than normal guys Max you might want to consider that. Reduced pixelation is another benefit of DLP. LCDs were always known for their visible pixel structure, often referred to as the screen-door effect because it appears as though the picture is being viewed through a screen-door when you stand within 5' of the unit.
Mitsubishi has the best picture IMHO. Sony is not bad but look at their service history before you buy one. I did home theater installation work for while as an independent contractor. The owner of a very large and busy electronics repair shop I contracted with loves all the work he gets from Sony products but complains that their connectors, sockets, and almost every part has a proprietary shape unique to them. You have to order Sony parts or you are screwed. I steer clear of Sony now.
My next unit will be the 62" Mitsubishi High Def DLP. Here is a
Plasma vs LCD vs DLP comparison. What ever you choose enjoy!