Good Deal! Progress...
For a data point or two, I have a 5000mAh 6s1p pack from JetWerx that weighs 25 ounces,
and a 6000 mAh 6s1p JetWerx pack that weighs 29 ounces.
That might tip you off to approx battery weights. Of course, I have no idea what mAh you'll be needing.
For the pic of the model being tossed off of the cliff - was it powered by the two Byro Fans? or was it flown as an unpowered slope model? Just curious...
Keep on building!