Audit --> Corporate Acct --> Corporate FP&A OR Big4 FDD --> MBA

I have a specific question for my current situation and would be curious to hear what people think:

I had ~2.5yrs Big 4 audit experience and then left for a corporate accounting role in the healthcare technology industry. The company is public but still small enough that I wound up splitting time about 50/50 doing corporate accounting and FP&A, Reporting, and analytic type work. This includes revenue forecasting and working to identify and report on key KPI's. I recently received a job offer from Big 4 to enter their TAS FDD group at a level 3 senior associate. My boss at my current job informed me that both of our roles will be transitioning into a pure FP&A function over the next year. I am also currently studying for the GMAT and will be taking the exam before fall; i plan to start an MBA program in fall 2016.

This puts me in a tough situation. My end goal would be to work in PE, Corporate development/Strategy related specifically to the tech industry after getting my MBA (from a good school).

Questions:

What looks better to Top MBA admissions? The M&A FDD experience or going from corporate acct into a FP&A role at my current job? The company is public and a real player in their market space, but not a huge name brand like IBM or something.

What would be better for my end goal of PE or Corp Dev?

Also, can anyone with FDD experience at Big 4 shed some light on the more accounting and more finance related work in the job? Are you evaluating assumptions in the financial forecasts of target companies? Do you get exposure to the financial modeling at all or are you just basically just an auditor who audits balances and values that are crucial to the target company's valuation?

thanks.