What made you leave Berlin, if you don't mind sharing a bit more?
Finding the right place is always a compromise. E.g. :
1) quality of schools for your son (eventually; he's still super young)
2) VISA, how easy it is to get a permanent resident, and/or citizenship
3) Island close to the equator: the weather is usually not that great (source: lived in Singapore, an island close to the equator, for 2.5 years). But picking the right "type" of place is important, and I suggest you take a 1-month long vacation in 2-3 places, if you can afford it, to "test" it and see if you like it.
Still on this point, I think that most "north Europeans" enjoy the mediterranean area (Portugal, Spain, Italy, or even Greece). Have you tried it out?