Can a US Citizen applying for a Tier 4 student visa after entering the UK? [closed]

I was recently offered an unconditional degree program of study at London Metropolitan University. I would be there for four years and I am very much aware that I need a Tier 4 Student Visa. I just found out a few days ago that I was accepted and I'm due for enrollment at the end of September of this year.

I'm have a huge time constraint to acquire the funds for the visa application. I can have the maintenance and living fees in my bank account by the end of September, but I don't know if I'll be able to have them there for the 28 days Immigration is requiring. I'm concerned that my visa application will be denied for it if I apply before then.

Is it possible to enter the UK as a US citizen, with a pending Student Visa application, begin my studies at school and then be approved for it? Should I enter the UK as a visitor, begin school, and then, very soon after, apply for my Student Visa once the funds fall into the 28 day period?

Gathering nearly $14,000 (US) in a few months and holding it for 28 days isn't easy as they stress it has to be.