I am building a 108" C-130 from scratch. This bird will have retracts, brakes, fowler flaps, functioning ramp/door, cargo rails, and will be used to airdrop pallets, Jeeps, ect. I am quite a ways into the build and have several questions.
1. This aircraft will have a modified flat bottom airfoil, a wingspan of 108", a chord of 12.5" and about 2.5" of camber. I don't want to overbuild this thing but am worried about the overall strength as I have never done a complete scratch build. It goes without saying but i have no intentions of pulling high g`s in this bird.

My initial thought is to make a 1 piece detachable wing using 2 parallel boxed spars, one 3" aft and one 9" aft. This is very similar to the actual aircraft except it uses I-beam spars and the outer wings detach outboard of the #2 and 3 engines. I would love to set up mine to detach the same way but don`t want to create a weak point or add the excess weigh of aluminum tubes or carbon rods. I was planning to use 3/8x1/4 or 1/2x1/4 hardwood for the upper and lower parts of the spar and 1/8 balsa for sheer web. I am hoping that someone with a little more experience could give me some insight, i would estimate that the fuselage will weigh between 8 and 10 lbs. fully sheeted with radio and servos. all of the fuel/batteries will be in the wing aft of each engine or in the aft nacelle, this should help with wing flex a bit. This brings me to my second question

2. Power plant: First of all i need to decide how much thrust i will need, I planed to use 4x .25 or .35 glow motors, however i am terrified of syncing and keeping 4 glow motors running. I also thought of using 4 electrics for reliability but have ZERO experience with them. Thoughts?

I took a picture this morning while cleaning the garage to show where i am at