Desperately want to go to China and stay there for maybe at least for a year, how to go about it?

Hi :-P
I'm a UK citizen currently living and working in Donetsk, Ukraine and really want to go to china and stay there for maybe at least for a year but don't know how to go about it.

I was reading about the different visas and first was wondering is it possible for me to obtain any of these visas as a UK citizen living and working in the Ukraine, as an airfare ticket back to London is expensive and would like to go to China directly from the Ukraine if possible.

1. If I go on a tourist visa can a UK citizen also extend their stay there twice more? allowing me to be in China for at least 3 months? Then if I manage to find a job whilst I'm there during these months will I be able to apply for a work visa already being in the country, or would I have to come all the way back to England to restart the work visa application process from there?

Also I was thinking if I don't find a job and decided to study instead, would it be possible to apply for a student visa whilst already being in China ( after extending my visa twice already if possible) or would I have to leave the country. If I did have to leave China would it be possible just to go to a neighboring country instead of all the way back home to England.

Last question :) ( I hope I get a reply)))) would it be possible to apply for a business visa for 6months whilst already being in China ( on my now twice extended tourist visa if possible) and can my friend who is a Ukrainian citizen studying chinese as a student in a university already living there make a letter of invitation for me? or are letters of invitation only accepted from companies and not individuals?

Thanks sooo much in advance for your response.