I have not done this, but I can fairly accurately warn you of two problems.
First, you will need a separate SATA controller, which may or may not come bundled with the enclosure. Just read the link - no, it does not. Port Multiplier technology is NOT a common feature of SATA controller ports. If the SATA controller on your motherboard does not support it, then you will see only one drive.
For example, see this product:
http://www.newegg.com/Product/Product.aspx?Item=N82E16816132015
Second, while most of the people on this forum will use such an adapter bracket, it is out of spec and should never be relied on. The signalling voltage levels for SATA and eSATA are different. They overlap, which is why this usually works, but...