As far as I can see you are have everything all figured out. Your motherboard does support SATA. IF you have SP2 then you should easily be able to see more than 137 GB. I'm also sure that the connector you have that came with your Motherboard is exactly what you need. Most motherboards come with a connector. You can use that Power Cable, but the Drive I recently bought also has the regular 12V connector on it. It doesn't matter which one you connect but DO NOT connect both of them. Here is a picture of my SATA WD HD.
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2179837&CatId=139
I highly recommend this HDD too. Tigerdirect.com is a very good website. Although there wasn't a rebate when I bought it
I would also like to suggest that you look to see if your motherboard supports SATA-150 or SATA-300. I couldn't find it on the website you gave so I am guessing it is SATA-150. SATA-300 is supposedly faster but you won't notice any difference in speed at all. The reason I suggest this is becuase some SATA-300 drives need to be configured to run on a SATA-150 motherboard. To do this, all you have to do is place a jumper pin where the Slave/Master settings were located on the old IDE drives. It explains how to do that on the Hard Drive. Its not hard to figure out but I thought I would make sure you knew about it.
Just for the record, SATA is much easier to work with than the IDE drives.
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2179837&CatId=139
I highly recommend this HDD too. Tigerdirect.com is a very good website. Although there wasn't a rebate when I bought it
I would also like to suggest that you look to see if your motherboard supports SATA-150 or SATA-300. I couldn't find it on the website you gave so I am guessing it is SATA-150. SATA-300 is supposedly faster but you won't notice any difference in speed at all. The reason I suggest this is becuase some SATA-300 drives need to be configured to run on a SATA-150 motherboard. To do this, all you have to do is place a jumper pin where the Slave/Master settings were located on the old IDE drives. It explains how to do that on the Hard Drive. Its not hard to figure out but I thought I would make sure you knew about it.
Just for the record, SATA is much easier to work with than the IDE drives.