Is this the best option for HD or should I get something else?

Absolutely, easy to set up, produces great pictures and it is very mobile in easy carrying case.
It should work fine; this is suitable for HD, as it has the ratio 16:9. The size dimensions are fine, and there are no better screens if you are looking for HD picture quality. For the price this is a great screen.

For more information please check out our guide setting up a great backyard setup
http://outdoormoviehq.com/ultimate-guide-to-outdoor-movies
Or take a look at our recommended projectors and screens
http://outdoormoviehq.com/outdoor-movie-screens