Adaptec makes some good sas / sata controllers, check out the new 5 series. Might be cheaper, though, to migrate some of your 'stuff' to your new drive. External USB enclosures come to mind, as well as Acronis.
/ start lecture/ Wouldn't it have been better to have thought this through first? / end lecture/
What was the reason for buying a new drive? If one of your drives is running out of space, replace it with the new one, perhaps partitioned proportionately.
Sorry, but this does look like something that needed some more planning.