Christian, for what it's worth, if you want to be left alone and have the least amount of red tape to live off grid, politics, economics and social conditions are the Number One consideration. Your neighbors, if they don't like what you are doing, or you seem to be getting away with something they didn't (like illegal buildings unpermitted wells or 10 people living without a permitted septic tank), and you all seem kind of odd to them, they will be the first to turn you in. Now that Google Earth keeps any eye on everyone from the sky, anyone can see what you are up to, doesn't matter where you are.
Buying land may not be difficult, and the land may be paid for or get paid for in time, but taxes are forever. You want the least amount of property taxes, but the minute you improve it by building the taxes will go up.
Not sure how old you are, but my guess is 10 friends now, may not stay together forever, or partners will come and go shrinking or swelling your ranks. People grow and change, so whomever is left paying for your situation needs to be able to afford it well into the future without the help of the original 10 friends. And, of course, all the legalities of who owns the land ought to be written up before the money is spent. In fact, agreeing on and buying land may be your first indication of how well this group actually gets along under real life conditions
Mediterranean climate, hugel trenches, fabulous clay soil high in nutrients, self-watering containers with hugel layers, keyhole composting with low hugel raised beds, thick Back to Eden Wood chips mulch (distinguished from Bark chips), using as many native plants as possible....all drought tolerant.