digital to analog conversor

Hello people..

I would like to develop a small signal generator (mono and triphase) using pic (maybe 16f88 or 16f629).

It would be necessary a DAC to create a 60Hz sinusoidal signal. Well, it would be interesting a serial dac, but i can't find it here where I live.

I've been working on a project using 32-bit DSP and I need to get some results by modifying this 60Hz signal (like perfoming sags and swells on the signal).

So, i think i'll have to use some paralell dac but, is a 8-bit dac gonna be enough? Should I look for 10 or 12-bit dac? Has anyone already played with 60hz sinusoidal signal?

well, thanks in advance..

Sylvio