Well, I'm assuming that your talking about the center section that your glassing, if so, then your close, the problem with thinning the epoxy with alchol is it will become kinda rubbery. With 30 minute epoxy, you can heat it up in a bowl of hot water to make it less viscious. I would recommend doing the top and then the bottom seperate, it will give you the time to do it nicely and avoid screwing it up. Another trick is to put down a thin layer like you said, put down the glass ontop and then squegie the resin through the glass, then take the backing material from monokote( the clear stuff) and place it over the glass and squegie the plastic down smooth, let it dry, pull the plastic off, it won't stick. It will be smooth as glass (pun intended) and the edges will have the excess epoxy creating a small transition fillet from the glass to the bare wood. This minimizes sanding, therefor cutting down on time of trying to blend it to the wood.
But, here's the deal if your planing on using it for glassing the entire wing, DON'T DO IT! it will kick too fast for you to be able to get the entire panel done in time. Your better off buying the finishing resin, or west system,MASor system three resin and slow hardener.