For the upper center 22" screen, I used an ergotron. Was on sale in circuit city for $50 when I got it




That one does droop, which is to be expected for the design. It is not really tall enough to use it the way I have it set-up. I did a ghetto fix for it by getting a small $10 table clamp at home depot and bending a steel bar into an L shape, clamping one end onto the table clamp and then using the other end for the ergotron mount to clamp onto.