Hey, I use Sonar 5, but whats wrong with Pro Tools? Isn't ALL recording programs out there allow you to capture the "moment"?? a majority of the recording studios out there has a PT rig or few.
btw, your going to need a WHOLE lot more than $500 dollars to get any sound worth listening too. An interface does not give you 'studio' quality. It's also not JUST the gear, although it plays a nice roll, but it's also the knowledge of the producer/engineer. Just by knowing what your doing, your music can sound -better- regardless of your setup - to a certain point... anyways, like suggested, the Firepod should be fine for you, depending on what exactly you'll be doing.