Lighter (not lightweight) battery from regular auto part store?

I know there are plenty of threads about the lightest battery options... but what are are the lighter batteries that have the same height/width as OEM battery that you can buy at Autozone/Advance Auto/Walmart? Should I just measure all the batteries and pick one that fits and has at least 450+ CCA? Or is there something special about the recommended H7 batteries (besides the 750+ CCA)? I have a 2001 BMW 330Ci.