I just wanted to check that this type of blog (discussing nitty-gritty details and construction and stuff) is of interest to you ... or would you rather that I talked only about the electronics side of things?
@Max I was going to suggest you used one of the usual TV ratios of 4:3 or 16:9 but I think @perl_geek's comment
You might want to consder employing the Golden Ratio (1.618 : 1, close enough for government work) in your rectangular layout.
is spot on - old TVs were't wide enough and new ones (16:9) always look too wide to me. I did come across the Golden ratio, as the Golden rectangle, years ago and the Wikipedia artilde on it is good (if a little over my head maths-wise :-) :