To start with, the G36 had some problems on the early models. Later models apparently work just fine.
The G26 is a proven pistol in a proven round. Some of the +P rounds are more than ample for SD, and it carries a few more rounds than the 36.
Will you be satisfied with the 9 mm, or is that a second choice?
The G27 in .40 will have a bit more power in the same size gun, and it can shoot 9mm with a conversion barrel and G26 mags. Another option. Or you can jump up to .357 Sig with a Conv. barrel.