Financial economics is a lot better than Accounting of course. But, be very active and focused as Finance with Economics can be tough depending on the requirements.
As to Chris’s post, I am sure if you do Accounting, you will be a lot better off in grasping the main idea of the Accounting texts than anyone else. You will not have a lot harder time preparing for your exams. It can be achieved if you have your degree done very well at the university. Many grads with different backgrounds apply for Accountancy companies training programs but without fully understanding Accounting. They know that Accountats get paid well as their career progresses but to get to that level without professional qualification is not easy. Prior knowledge of Accounting will, to some extent, make it easy for the trainees to pass ACA/ACCA/CIMA and obtain their qualifications.
Bear in mind, although, BIG4 provides you with trainings, you will be working full time at the company. Keep in mind, while training, you will be working long hours(audit seasons), this means you will have little time to do reading. If you have Accountancy degree then it is obviously your Golden asset.
Whatever you do, get at least 2.1 while doing your degree, try to do Finance/Accounting related optional modules as they will provide you the basic knowledge. You will be better off.
If you do Accountancy, this shows your committment to the industry.
Anyway, good luck with your studies.