Applying for a Tourist Visa Extension vs. Applying for a new one

Hi There,
I currently have a 1-year multiple entry L type that I got for a 3 week trip through China in June. I am now planning on returning to China for 3 months, but mine a is only for a 30-day entry.

I'm wondering if it makes more sense to apply for a new 3-month entry one while I am still in the US, or if I should just apply for extensions when I am in Beijing. Which makes more sense?

A final question: My round trip flight is through Hong Kong, and it is for a total duration of 5 months, because I am going to be traveling in Southeast Asia and India after my time in China. Will a 5-month round-trip ticket at all hinder my application for a 3 month L type, should I submit any explanation with my application?