For that model it looks like your interface is ATA-6. I do all my computer shopping at Newegg(.)com. But if you can find them cheaper at the B&M stores, go for it.
copy and paste the text (almost made more than 5 posts!!!)
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newegg.com/Product/ProductList.asp?N=2030150380+1035907889&Submit=ENE&SubCategory=380