I suggest the Apex stand also. When I was using my laptop, the second tier held laptop nice and straight, as high or low as you need or want.
BTW - am I the only one who understood Shim to mean that he wanted the second tier to bend to become straight? I think we see many double keyboard stands with the upper keyboard tilted. He wants his second tier to be straight so the laptop won't slide. Am I right, Shim?