Do you have any big fishes in CA besides sturgeon?
I have a couple of rigs that I use, mainly spinning rigs and casting rigs; none of them cost me more than $100 to set up brand-new, and they all work great. Generally, if you're going for big fish, e.g. stuff that weighs more than a couple of pounds, or using lures, then you're going to want a casting rig or even a conventional reel like what people use for saltwater fishing. You can use a spinning rig for the little stuff; they're not as useful for bigger fishes because they don't have a very good drag. Casting reels can take a little bit to master, especially the open-faced flat ones, but they're a breeze to use with a little bit of adjustment and some practice; I found that it's easier to start with a round casting reel and slowly adjust it & practice casting before taking it fishing.
For an example casting rig, you could get an Abu Garcia BCX 6600, a 6'6" Shakespeare Ugly Stik (Model CAL110266, Line Weight: 10-25), a spool of 20 lbs. test Cajun Line Red Cast monofilament, some bigger circle hooks, some weights, and some swivels for around $100 at your neighborhood Walmart (or some other store that sells fishing stuff). Such a rig would work great for bigger stuff like larger catfish and smaller sturgeon since it has plenty of drag, a decent gear ratio, and plenty of backbone to take the weight of the fish.
As far as brands go, I favor Abu Garcia when it comes the casting reels because their quality, durability, and prices can't be beat; their round reels (BCX, C-series, etc.) will last you for many years to come with very little maintenance and a little bit of spot cleaning. As for spinning, I personally like Okuma, but there are many other good brands out there, too, such as Quantum and Shimano. When it comes to rods, it's hard to beat a Shakespeare Ugly Stik for value; they're pretty good for their low price, and there's probably an Ugly Stik for any fishing situation and rig out there. One thing to keep in mind when buying rods is to get a casting rod for a casting reel, a spinning rod for a spinning reel, and so on; mismatching them results in poor casts and other issues.