Approximatly 5.5 feet viewing distance is the where a the full detail of a 1080p 42!! inch TV can be made out by a person with 20-20 vision. No doubt some people are better, and others notice less, but thats the "baseline".
A 32inch at 8ft... there's really no need for 1080p, even Pal SD is "sufficient" at that size/distance, unless you have insanely better than average eyesight.
8ft viewing distance 720p 42inch
12ft viewing distance 576p 42inch.
Its really not worth spending extra money to get the higher resolutions if you go to small, or sit too far away. On the other hand, if the prices are right, a higher resolution wont ever make the picture look worse.