This type of bench I have been using for meditation some years now. Experiences with normal meditation postures appeared to be too painfull and the the use of a seiza bench gave me lower back problems. Unlike the seiza posture this bench is meant for cross-legged sitting; the lower legs can be placed under your buttocks.
This solution has some advantages over the use of a seiza bench or a chair:
The only disavantage is this bench is less compact then a seiza bench. On the other hand, there is no need for a thick cushion (zabuton).
This bench is very easy to make yourself. Because it is less compact I have made it foldable and portable, so you can easily take it with you. I am rather tall (6.3 ft / 1.94 m.), so the ideal measures might be different for you. However, it is best to wait with modifications until after you have done some time on your bench; shortening the width and lowering the height can be done later.