I just ran the numbers again, this time with a 8x6 4 blade prop with a 4s battery. It comes out to be 72 ounces of thrust at 30 amps. So 72 x 4 = 288/16= 18 pounds of thrust. I know you wanted to use 3s batteries, but with the lower KV rating of the motor, you might need to use a high voltage to use a smaller prop.
Now, if you want to push the limits, if you went with the 9.3 inch separation, you could use the 9X6 4 blade prop on 4s and get 21.5 pounds of thrust. That is an amazing amount of power out of those little motors. I think this would be over kill and would let you almost hover your C-130. It would take of at near vertical.
Here is the calc program I use. If you use the eflite motors, Tacons are close to being a copy of them.
http://www.ecalc.ch/motorcalc.htm?ecalc&lang=en
I would say use the 4s battery, 8x6 4 balded prop and you will have more then enough power.
There is a learning curve to all of this. It has been a long road for me. I have let the magic smoke out more then once. You might want to get a small plane and try the setup in. Just a stick type, easy to build test plane. That way you become familiar with all of this and can see what it is like if you change from an 8x6 prop to a 8x4 prop. It is better to crash a cheap throw away plane then a nice project.
Buzz.