The MPEG options are found in the render que when you "make Movie"

As with a few programms sometimes the default settings for sound are switched off (dont know why but this is the same for Avid Express Pro) so you have to play with the settings to get the desired result.

When I get home I fill post my settings for AE as I managed to get a 100+ Mb file (using the RAM Preview) to approx 300 Kb final rendered!!! That plays fine on media player etc..