the way they design televisions and computer monitors are completely different. the TV's resolutions do not go high enough for you to read text. the reson why is because a 27" TV is meant for the person to look at it from 6-15 feet while a computer monitor is designed for the person to be 1-2 feet from it.
it's not because TV's are designed poorly. just look at the price for a 27" TV and compare that with the price of a 27" CRT monitor and you will see what i mean. HDTV's are about the same as a computer monitor so i would guess they would work for what you want as long as you have a TON of money to get one.