Yeah Mulab is great, I have the full version and the Mux vst plugin that I use inside Reaper. MUlab is better at MIDI than audio though, depending on your needs the free version may be all you need. If you have $60 to spend, Reaper is the most powerful DAW for your dollar, though not the easiest to use for a beginner:
Another free option to consider is Studio One free....not that I have tried it, as I have the full version but prefer Reaper.
The motherlode of all free DAW and VST plugin links is at Bedroom Producers Blog, which is a great site: