Draw Leaf Table Mechanism

[Richard Strauss]

This is my first post. Am making plans to build a square 44"x44" mission style table with small 11" draw leafs. I plan to construct the table to look like there are two tops, one on top another, with the two leafs and a 11" center piece. I got this idea from a Stickley Furniture Company piece. The two runner mechanisms seem rather difficult for me. I found a mechanism at Lee Vally Tools to replace the runners called Parson Table Fittings. I would also be interested to hear your input on this table in regards to wood movement affecting the table and these mechanisms.
http://www.leevalley.com/hardware/page.aspx?c=2&p=41856&cat=3,43586,43594

Thank you in advance for any time and effort you offer to me.