Any of the methods will work, some better some worse. One key thing nobody mentioned is weight build up. Some methods will build heavier than others

A couple things to consider: water containing glues could warp the panels unless great care is used to select the same weight and type balsa for top and bottom. Contact glues have to be water based to work with foam. 3M77 has changed its formula and now it attacks polystyrene foam in all colors. In last month's Model Aviation, Bob Hunt describes a different product that worked well with PS foam.

Gorilla glue doesn't really need water to be spritzed; humidity in the air is usually enough to kick it off. Except, gorilla glue or Pro Bond or other Polyuretahne glue will likely kick off in about 25-30 minutes...it may not be enough time to lay down an even coat on a 50" panel, top and bottom skins. And if you wanted to do both panels at the same time, you are staring a time constraint in the face. Many guys use this method but you have to work fast

I have tried the above methods over a period spanning 43 years of model building. Have also tried the double sided tape method. It's heavy but also adds the strength of the carrier tape. You have got to be very careful and remove all dust from the foam and balsa with a tack cloth. Actually a tack cloth is very good to use for epoxy or gorilla glues as well. You need a dust free surface to produce the best bond possible

Over the past 25 years or so, I've used slow cure laminating epoxy to sheet wings. I have a pot life of 75 minutes with the stuff I use (Pro Set, 125 resin 229 hardener). I've found it to be the easiest and lightest method yet.

The easiest way to apply epoxy (and gorilla) is with a small paint foam roller from Home Depot. The rollers have a smooth surface and once lightly loaded with the glue you can do a sheet in short order. Take the roller just before layup and run it all over the foam surface. This will do two important things: removes any final bits of sanding dust from the surface and also deposits ever so slight amount of the foam, which makes the surface more receptive to the sheeting. The sheeting should look practically dry after you apply the epoxy. You don't want any puddles

Weighing down the panels in their shucks is the old tried and true approach to a finished wing. I suggest that you make sure the panels are flat during the cure. Measure the height from your surface to the panel center line.

Other method of holding sheeting against foam that I've played with: designed and built a press that compressed the panels during the cure. This worked well and required no heavy lifting. But the best and easiest method yet is vacuum bagging the panels, except this is a more advanced technique, where one uses the absolute minimum amount of glue. For your first wing, weights is the simplest way to proceed

Good luck