[Ron S]

You didn't mention whether you freedive or scuba, but in terms of your question, I guess it doesn't make much difference. There are a million guns, (well, almost), that will work very well for what you want to do, and fortunately, a 42" biller is one of them. You'll find it a bit too long for lings in thick kelp on bad vis days, and (rarely) you'll find it too short for rockfish on those occasional very good vis days. You'll quickly learn to make the "short shot" with a long gun, and your pole spear experience has given you the skills to close the gap on clear days. Overall, it'll do the job very nicely. My advice is that you avoid the trap I fell into of looking at all the other gun options and driving yourself nuts over what else you coulda bought. Keep that gun for now, and start researching a longer gun for SoCal, and then maybe later a shorter gun just for holes and the 3-4' vis days. The biller is a good rugged gun that'l kill anything you encounter and still survive the rocky coastline.
Ron.