I'd suggest going after a Cruel Mat's of Evis with +3 skill if you're using that for cowing. or of Amp dmg :P

Cruel Mat's bow (300%) +63 max can do:
84 - 255 dmg.

EDIT:
Bows
IAS needed for certain firing speeds
fps *[10] [5] [0] [-10]
15/4 0
14/4 4 0
13/3 11 6 0
12/3 22 15 9 0
11/3 35 27 20 8
10/3 56 46 37 22
9/3 89 75 63 42
9/2 120 102 86 60
8/2 147 125 105 75
7/2 292 240 200 142

Hope it won't look too bad...
The 7/2/ is what you should look at. 7 initial frame.