how long a course like this would take?

It depends of the level you want to acquire. Please, visit the following link:

http://london.floodlight.co.uk/london/courses-classes-lessons/best-acupressure-courses/qualification/study/region/16180339/220706/100/domain.html

There are different levels in shiatsu=acupressure. Some levels take in account the chacra's but for that I preferred the kriyayoga course that is specialised in that topic and origin fully from India. I'd advise to go for a basic course in shiatsu like I did in my country, and decide after this first step/level. It wasn't appealing me for further levels, to the contrary of kriyayoga what gave me much much more.

The beginner level, about six months.

helloooooooooooooo andrea how are you