Conference Visa categories and 4 Appican attandece need your visa office ?

Dear Sir,
Please accept my regards, I am Bangladeshi Buddhist Monk. we are my organization Invite 27th General Conference 14-19 October,2014 in Baoji, China.
So, My
First Question What categories should we apply(L,F/M,X,Z,G) ?
Sec rend Question Invitation Letter mail Copy accepted Yes or No ?
Third Question 4 Member to your Office Attendees Need. yes or No ?
With best Wishes,
Sujan Barua