The problem with blimps is that they offer no legal advantages over floating seasteads, as in being over national territory up to 200 miles out to sea still makes you subject of the crown or whatnot. And their technological / economical disadvantages compared to seasteads are too numerous to list.
Floating air-filled pillows is a super-simple technology, especially if unanchored (then you need a power source and a motor to keep yourself from drifting into government territory, but between solar, wind, and wave power that's easy enough to do). Then you just put a
gyroscopic platform on those pillows and you have yourself an island. There are numerous legal and social challenges to seasteading, but the engineering isn't at all prohibitive. Technologies like power generation, satellite Internet, and water desalination work pretty much the same way they do on the shore. The most sophisticated specific component of any seastead would probably be the vegetable garden.