There is at least one member on this forum from Portugal, perhaps they will chime in and be able to help you explore the true costs of the startup, and maintenance of running a fig orchard. They may be able to point you in the right direction of who might be able to help you with these, most of us do this for a hobby some have farms but a lot of us would not know what is required for you in Portugal as it may differ than in our countries.
Here in Canada out Government likes to help out farmers with such information, maybe yours will do the same if you contact them and be able to make recommendations of the best varieties for your area and weather it is good to have for fresh market, early, mid or late season, dried or a mixture of both in varying degrees.
Are you planning to put livestock on your farm as well? I know in Spain there are varieties that are used for feed for animals but not appreciated for humans and this could be another option for shelter trees who them along with Portugese oak.
I hope I didn't mis understand what you have done at your farm, Olive trees are very nice as well so you can have your own olive oil if you can muscle the work.
I wish you luck in finding investors and hope you have (and post pictures) success in your farm.