Sorry to here about your unfortunate experience. Even more sorry to here that you are in Cali where if you did come home to the burglar, you would probably be wrong to do anything but call the police.
Please take a look at this security system. You buy the system outright, meaning there is not a rental fee or contract or monthly fee. If you wish to have it monitored by the police or by your phone, there are options for that. The monitoring center for this company is the same ones as the big name companies (they just contract it out like Brinks, ADT, etc.) Also, you can customize the kit to fit your exact needs and you install it yourself. Best of all, you can take it down and move it easily. Also, it works off cell phone towers so no phone lines to cut. Here is the link:
Camera systems usually cost $300-600 for a decent system. Just make sure you hide the DVR or get one that automatically uploads the video to the internet so the thief can still be caught if he decides to steal the DVR.
If keeping your guns in your truck becomes unfeasible, think of places in your apartment to hide things. Return air vents, behind water heaters, in freezer under the meat are all good places to stash big things like guns. For small things you could install a fake plug in the wall and nobody including your landlord would know any better. Check out this link:
Just avoid hiding things under furniture, between mattresses, behind pictures, behind or in bookcases as those are common places for a criminal to look. Think about what the burglar trashed and what he didn't look through, then hide your items accordingly.
Lastly, good luck. I sincerely hope that you don't get hit again. Unfortunately, the statistics are not with you on that one.