I've been asked by a few companies in South America (both Argentina and Brazil) if I would go over and run short 3 day training courses for their executives.

Because of the length of contract I'm unsure about what visa to apply for. If I where to do this (financially it's difficult to resist) I wouldn't be living in a fixed place and I'd be flying between Argentina and Brazil every few weeks.

I've heard mention of using an Umbrella company. Does anyone know how these work? If so does anyone know of any good international or South American specific Umbrella Companies whom I could work through?

Would I still require a working visa (for three days at a time?!?!) or would I come under the Umbrella companies employment? Would I need to be paid in the UK or the foreign country?

Basically what I'm trying to understand is how I can work abroad for a very short amount of time and how I'd get paid?

Thanks