I'm British, float between Portugal and Brazil. See my paying customers as being US, Canada, AUS, NZ and UK. Want the simplest structure, banking, accounts obligations and tax. Initially I don't need to draw revenue, my plan is to grow subscriptions, I expect to get attention, and down-road would entertain investment if that door opens. Initially my focus is simple old school approach of getting paying customers, and proving the business model works.
It's really impossible to answer this question without a fuller analysis of your specific tax situation. "Float between" won't be the terminology used in a tax treaty!
That being said, we've attempted to distill down different incorporation options at Incorporations.IO which is a free comparison tool for looking at global incorporation.
Also there are plenty of articles on our FlagTheory.com website which talk about tax residency, bank accounts, obligations in terms of reporting and more.