Buy the Virtavia B29 and add CSWeapons you will not be disappointed.

http://i13.photobucket.com/albums/a267/bdenner/B29BombDrop.jpg

This is the weapon configuration:

       <Weapon>
           <!-- weapon sub-type section. unlimited number of -->
           <Gun>Mk82_500</Gun>
           <!-- weapon sub-type name. must match GunInfo>Gun>Name -->
           <Shell>Mk82 Bomb</Shell>
           <!-- shell name. must match GunInfo>Shell>Name -->
           <Unlimited>0</Unlimited>
           <!-- unlimited ammo fire. 1-yes, 0-no -->
           <Station name="Forward" params="0,3,-0.5,0,-4.712389,0,20" />
           <Station name="Aft" params="0,-2,-0.5,0,-4.712389,0,20" />
           <!-- Station position (x,y,z) meters, angle of incidence, ammo units quantity -->
           <Mode name="AUTO" shotrate="8" setshots="40" sequence="1,2" reset="0" />
           <!-- fire mode section. unlimited number of. name= dispayed on HUD in weapon info string. -->
           <Mode name="X3" shotrate="10" setshots="3" sequence="1" />
           <Mode name="SINGL" shotrate="10" setshots="1" sequence="1" />
           <Mode name="SAT" shotrate="8" setshots="40" sequence="1" reset="1" />
           <DefaultMode>AUTO</DefaultMode>
           <!-- default fire mode. Any from the list above  -->
       </Weapon>

You can use my Bomb Computer from here:
http://captainsim.org/yabb2/YaBB.pl?num=1297996771/30

READ the whole thread as I will not be adding more instructions!