I work with John James milliner size 10 needles, but they are 1.5" long. A size 3 milliner would be longer. The John James size 3 are 2.203" long. Size 1 measures 2.328" long. In my experience, that seems to be pretty standard across brands. The downside, of course, is that a Size 1 is twice as thick as a size 10, so you will end up with a larger hole.
Here's a link to the length & width of different sized milliner's on the John James website:
http://www.jjneedles.com/buy-needles...tml#size-guide
It's in millimeters, so you'll need to convert any measurements.