Run & Gun has the actual SWAT armor, some good weapons, and a bunch of called shot and combat rules. I suggest it.
Run Faster has a bunch of qualities of variable value to you. It isn't a necessity, but it is still a decent book.
Chrome Flesh has 'ware, although the book's index is unenviable and it makes the entire thing difficult to search through.
Run & Gun and the Core are the only ones you'd need for your build, I think. Run Faster and Chrome Flesh would be good additions when you find the cash (or buy them as a group to split costs, always helps).