Have you tried Louisdog? They have some great functional jumpers and their jackets usually have removeable hoods and embellishments so you can tone down the 'cute' if you're not into it but still get a great fit. The jackets are made with the 3M Thinsulate so they're super-light but really warm. Nibbler has a 7" neck, 11" girth and 9" back and size small in Louisdog fits him generously and the length is always good.
I was also looking at this woman who custom makes jackets which look great:
Nibbler also has a few doggiejama fleeces which are amazing quality. He wears the 25cmbut she also custom makes. You could take advantage of our crappy Australian $ and probably get one at a good price even with shipping.
Warm Winter Fleece Dog Jumpers - DoggieJama - (Powered by CubeCart)
Good luck finding something that fits well and is suited to what you want it for. It frustrates me that there is almost nothing in Australia that fits Nibbler and I have to buy everything from harness' to jackets from overseas. The things we do for our little guys. 😉