Hi. The resolution of the DAC should come with the specs. What should be the output step?
The resolution and frequency depend on the topology. Like most designs, if you choose a topology which allows high resolution like sigma-delta, it is expected to come at the expense of limited speed (frequency)
If I were you, I would choose a particular topology that satisfies my specs. After that you can search for a good available Master/PhD thesis document or a detailed journal paper and start your work based on it.