Sure Steve, this is what we do based upon recommendations from many experienced sources.
The tank is one of the Paradise blue soft sided tanks with the zipper close tops. Can't remember the amount of gallons or measurements, but I'm sure it's on their web site.
I do not fill to the brim. We fill to about 5 inches from the top and then cover with one sheet of 1/2 pink house insulation cut to size with a hole in the center for the air stone lines to drop in. We've tried many different way to reduce sloushing, but this seems to work the best for us. Can't avoid it all together, but this seems to reduce it quite a bit.
Elbagin? Only about 1 gm for this size tank. You really don't need much.
We've had up to 5 fish in that tank overnight (about 24 hours all together) with no problems. Most were in excess of 22".
I only add straight 02 to the tank at the last 6-7 hours of transport. This brings up the whites and the fish seem less stressed when moved into the show tank. I use the low pressure 02 tanks that you get at the hardware store that welders purchase. You have to get the valve kit so you have a regulator - cost is about $50 - discard everything but the right valve. I "meter" the flow simply by "eye". Too much and you can burn the fish. I allow only a very few small bubbles to come through the air stone. That's all you need. Kevin Pham gave me this tip. He says they do this in Japan often. I've tried it one time and it works like a charm!! The fish look better coming out of the tank then when they went in!!

But you have to be really careful about how much 02 you force into the water. It's a very efficient oxidizer that can burn or even kill your fish.
I hope this helps!!