Suggestions on HDTV viewing height

I just bought the Mitsubishi 73" DLP and was looking for a A/V stand that would house my audio components and of course, the TV. Salamander makes a few good stands but the triple shelving (65.75" W) comes in two heights 31" and 21". I feel the 31" stand will place this large tv up to high slightly above eye level whereas the 21" is almost eye level. My viewing distance is 13.5' and the room is 18 by 15. Any suggestions would be of help
Sit in your viewing chair as you would normally. Make certain that your screen is positioned so your head does not have to be in an uncomfortable position to take it all in. Enjoy.
I would mount that to the wall and never to a rack with a vertical bracket, putting it on the wall will give you best and most stable results, my dad and I just bought a 60' plasma and yours surely weighs much more, no safer place then on the wall under a low Salemander rack (wich my dad also purchased).
Ergonomic studies with respect to computer monitors suggest that you should be viewing with the screen just slightly below the horizontal level of your eyes. I see no logical reason why it would be different with a TV unless the fact that you are farther away makes a difference. I can't comment on that. So I would second what Dtsag says and suggest the 21 " stand.