I think Rocks are a little slimmer than most. At least my #2 seems to be.

In 7mm, I'd go with a #3 and keep it under 23" with a modest shank. A Brux 3 with .25-.5" shank and 22" would be a nice in a lightish' handle. Flute it if you don't like weight forward.

“Life is life and fun is fun, but it's all so quiet when the goldfish die.”