Visa for china

Hi Everyone,

I am planning a cycling trip that will start in July of this year. I will be flying to Uzbekistan and will cycle through several central Asian countries. The visa's for these countries seem fairly simple to obtain but I am having some slight issues in how to obtain my Chinese visa. I am aware that i will have to apply for my Chinese visa in the UK before I go. Here are some questions that i have listed below?

1. Do i have to go through an agency to get my Chinese visa, as the fees all seem quite high?

2. Is it possible for me to cross from Kyrgyzstan into the xinjiang province of China as I've heard from else where that I shouldn't mention on the visa application form that I'm travelling to this area?

3. Does anyone know if it is possible to get a tourist L visa that will be valid for 6 months from the date it is valid?

4. The most ideal type of visa for me to get would be a tourist visa that has a validity of 6 months from date of issue and is valid for two months when I cross into China. Does anyone know if this is possible?

Thank you very much for taking the time to read this and would be most grateful for some guidance of how to go about some of the issues I am having.

Many thanks

Daniel