Adequate Maintenance Income

[eric10]

I am hoping to apply for my wife's spousal visa in November via the adequate maintenance route as I receive DLA.

One of the requirements is that I have to show a bank statement showing the money being paid into my account over the past 12 months. However, my money is not paid into a bank account and is instead collected from a Post Office every month. Will a cover letter explaining this be sufficient or will I need some other evidence in place of the bank statement?

Additionally, what income from jobs counts towards the earnings from employment? Do they need to be held for six months to count, or is any length of employment fine as long as the job is held at the time of the application?