Do you have a particular passion to be a tax accountant? If so, pursue it!
The fact is, both will set you up well enough. Audit probably had broader exit opportunities in the traditional sense, but in the literal sense it's you're career and you can do what you want with it. If you decide you want to study tax for 3 years then become a financial statement type of accountant, I bet you could. If you decide you wanted to study audit for 3 years then become a chef, I bet you could. If you decide you want to study tax for 3 years and then become an auditor, I bet you could. You get my drift?