SansDigital MobilStore MS2UTN + B 2-bay Enclosure

[MSwhip]

Having read your rave review of this Dual Bay Enclosure; extensive as it is and before I buy his product I
would like to ask the community a few more things.
Your review # 6633 for a: SansDigita-sans-digital-mobilestore-hard-drive-enclosure-review ....(this system wouldnt let me post the link on this page cause this now is just my first post of a thread), id like to ask the following questions: it says. that it comes with a bracket (is this PCI or PCI express?) with a cable to connect to the sata port in the motherboard, said cable is 1 fy long according to teh manufacturer. My computer does not have yet an e-sata external port on the back of the tower. Would this port on the bracket become an e-sata port now? No need of any controller to make the enclosure work? The mother board shows 4 Sata ports. Sata 0 used by the Master HDD 2 TB, Sata1 used by a Slave HDD 500Gb and Sata 4... with a an orange cable to the DVD-ROM Drive.
So that leaves me with port Sata 5 for this new enclosure addition.
On the back of the Desktop tower.. I have 4 slots for cards, From top to bottom i have slots 1 and 3 used with Video Card and Tv Tuner Cards respectively; slots 2 and 4 are unused. Could I place this bracket with the e-sata port on either of 2 or 4? ...or one of them is PCI card...and the other one PCI express and i should use one of the 2 specifically?

I would appreciate any input from knowledgeable minds, personally I have very limited skills on these issues.. barely a 4 out of 10, so please in layman's language.

Thank you kindly