Reaper has a lot of miniatures posed the way you describe.
Just head over to their store and seach for "staff" and you should find plenty
If your not into reaper mini's, and its gotta be metal, id suggest you take a look at a site like Wayland games, they host a bunch of different companies, so that should broaden your seach
If your into a bit of conversion its quite an easy pose to accomplish, kinda like what I've done with this vampire?
Another option is to go plastic
most boxes come with a banner, and many has a pointing arm aswell. So a trip to a bit-shop could solve it, and allow for exactly the mini you want
This one is made from the highelf archer box, with a few Bretonnian bits and the book from the mordheim sprue