Starter Motor

Hi Guys, After doing various mods and trying different ideas, my starter motor on the 1200 GS 2008 is still dragging sometimes, 8 out of 10 times, so have decided to replace the starter. I did read some time ago about a non original starter that will fit/work, but now can't find that thread. Mine is a Bosch, BMW part no.
  1241 7 691 956 03.
Bosch No. 0 001 106 409  (410)
Can anyone lead me in the right direction?
Thanks