Welcome Radiolady. Welcome to the site. An old girlfriend of mine moved to LA who was in the "biz" in Portland. Don't think she is doing any radio down there though.
Anyway. It really might be the most economical way at this point to maybe just hire a studio for a couple of hours to produce your "demo". They will have all the necessary gear, and probably an engineer that has some experience doing voiceover work for commercials that can get you sounding good.
You will need of course your script complete with sound effects you want, and wouldn't be a bad idea to bring along CD's of music you want to include on the demo.
It wouldn't take all that long to make many different "demo's" that reflect the different talents you want to display, such as voice over for commercials, station plug's, airchecks, and airchecks for different station formats. Obviously you wouldn't want to send a rock station aircheck to an easy listening station.
Anyway, if getting back in is your only goal, and you need high quality, I think hiring a studio is your most economical approach right now.
After obtaining employment, it wouldn't be such a bad idea to get comfortable using a audio editing package. Most DJ's I know here could edit the pants off of studio engineers I know.

It is part of the modern DJ's job to do commercials, station plug's, etc...So you can count on having to learn SOME audio editor at some point. But, don't count on it being a PC based software either. Many stations around here have turnkey "stand alone" editing systems that work much differently than PC software does.
Anyway, good luck in your job search.
Ed