This is just how K2 measures skis, they always come out a little longer. So a 179 like op should get is really a 182/183 but it doesn't make a big difference.
To Op: definitely get a 179. Domain's are incredibly soft and you'll want to get them as long as you can (179) for your height. I believe they are symmetrical? Making them feel even shorter when you've got your center mount.