I have been building these adjustable flight stands for some time now (ever since R.U.P. came up with the idea during our long-running VSF campaign). The actual process is rather straightforward and provides a sturdy stand that will happily hold most reasonably-sized models. For those of you who might want to build your own here is a step-by-step introduction to my method.
There you have it, cheap, sturdy and fully adjustable. You can find larger adjustable magnetic tool (often referred to as "mechanics hand" or "magnetic hands") at automotive tool shops, I got mine from Lowe's in the Craftsman section of their tool crib. Once finished they can be spray-painted as you like, I prefer to paint the lowest section of the metal tubes black and leave the others bare chrome.