Numerically, the 88mm flak was available in significantly larger numbers than the 105mm flak eg see:
http://www.feldgrau.com/weaprod.html
According to a very old reference (Sweetman,
Schweinfurt Disaster in the Skies) for the Flak 38 105 mm weapon weight of shell = 25 kg, muzzle velocity = 870 m/sec, range = 40,000 feet, rate of fire = 12 rounds per minute.
Not a lot to go on, but perhaps the above could be a starting point.
Regards
Boomerang