I would recommend getting one that doesn't have any sleeves. I think most dogs are a lot more comfy in the coats with no sleeves and then you can layer underneath and put on a thermal shirt with sleeves, like the ruff ruff couture thermal shirts or the hip doggie thermal shirts.
I have that exact puppy angel coat for Minnie ( that Christie posted a link to ) in a different color and I love it on her. its warm and comfy and I love how it has that zipper part to put the harness thru so they can wear it underneath the coat.
doggie couture is having a sale right now ... its 35% off and the code is Labor. the sale will end at midnight on Wednesday ( tomorrow )