I love Liv (never have assumed it's short for Olivia or anything else) and I find Stellan quite handsome. I do happen to like both Lars and Anders but I think Stellan feels more fitting alongside Liv.
I like Lars as wellHowever it's a bit of a joke name around here, along with Lena and Sven. Google Ollie and Lena jokes. It's too bad, really, I'd happily use Lars.