Hello Maple_leaf,
I'm unfamiliar with customs in Lebanon, as well as what crops are the most profitable in that region of the world. But I think your idea to promote hydroponics for food production in that area of the world, especially with such limited resources is a very good solution. However if you don't have any experience with hydroponics yet, I would also agree that you should start small first. Even starting now before you move their, grow a few of the plants you plan to make a profit from in Lebanon. That way you can learn to grow them hydroponically, before you spend a lot of money on the project. There is no substitute for hands on experience. Last thing you want is to spend all that money, just to learn something simple that may become a big problem later. Work out the bugs before going bigger.
I'm not sure what plants you plan to grow, but one of the best benefits of growing hydroponically is the ability to make use of vertical space. Building a multi-level
hydroponic system is a great way to make use of vertical space. But here experience with a smaller scale setup is going to allow you to make the best use of the space, as well as teach you the best way to construct it on a larger scale. Again, I don't know what plants you plan to grow, but with a multi-level setup, you'll need to work out some things like getting "even lighting" to all the plants, as well as "even water flow" (both to and from your plants). But probably even more important is how to deal with "maintenance issues" like cleaning the system (without damaging your plants), plant rotation and harvesting issues (again, without damaging your plants) etc. etc. etc.. You don't want to need to redesign your system after you already built it. You will also want to learn how to deal with the climate in that part of the world, before building the large greenhouse/s (assuming you plan to grow year round).