Within Theravāda tradition, what are the differences in doctrine and practice between schools and sects around the world? I'm considering spending some time in the future in retreats to have a taste of what monastic life is like.
It seems that Theravāda is the current tradition most related and compatible to my moral principles and philosophical ideas.

But before spending too money on flight and residence without complete certainty on the differences and traits of schools around the globe, I'd like get enough information.

So, as I've written in the title, what are the main differences between schools, lineages, branches and sects in the Theravāda tradition?

Also, only if possible -and if it's allowed by the forum's rules-, if you were to go forth, what monastery would you choose, and why?
(Just in case, I'm not asking what tradition is better or what is the closest one to the original teachings, because every sect can say that they're the ones).

Thanks for your time!
Have a nice day!
It appears that some teachers and traditions are more focused on samatha and jhana like Pa Auk Sayadaw and Ajahn Brahm.

And then there are other teachers and traditions that are more focused on vipassana like Mahasi Sayadaw, Ledi Sayadaw, Sayagyi U Ba Khin and his student S.N. Goenka, Ajahn Tong Sirimangalo and his student Yuttadhammo.

Samatha is cultivation of concentration and vipassana is cultivation of insight. 

Ultimately both are needed.