Given your description, I would also suggest Bentley. I agree with lss that get the visa first and apply in US. I do agree to give it shot if you might improve your GMAT. However, I don't think you need CPA for acc phd. I do believe GPA is overwhelmingly important. Get good grades, and try to start research early, get prepared for application early. good luck.
I can not reply your msg due to some unknown reason of the web. I also support Bentley. Yession already said most of what I wanted to say. If you go to Bentley, get(in the order of importantce): High GPA, solid economics and statistics training, a high GMAT if necessary, some research experience if possible.