I'm not an entrepreneur, but I've lived in the SF Bay area for quite a while. I'll offer a few thoughts.
LA is the center of the media, entertainment and music industries. There is also a lot of aerospace and related work in the area, which means there's a pool of qualified hardware/software engineers. San Jose is the heart of Silicon Valley and the electronics and software technologies. So I was intrigued by your statement that you'd be flying to LA, since I'd expect flights to San Francisco or San Jose to be more useful for meeting with electronics industry people. Is it that you plan to meet customers in LA?
In the Bay Area, there's a huge pool of qualified technical professionals in software and electronics hardware. But there's also a huge pool of employers. That works both ways. You can find workers, but if you don't treat them well and compensate them well, they can easily find other employers.
The cost of living is incredible in the Bay Area. Check out home prices on Zillow. It's hard to find a modest house for a million dollars. It's hard to rent an apartment for 3,000/month. Salaries are commensurate. Facebook's median salary is $240,000. Office rent is expensive. Taxes are high.
So be careful with the math. How long do you expect your 50 workers will have to work before your company starts making enough sales to turn a profit? It seems to me that it would be very easy for 25 employees plus 25 interns to burn through six figures of capital in less than a year.
But despite the high expenses, many companies do quite well by locating in the area, because the talent pool is great, and there are a lot of benefits to being in a place where there is so much electronics industry. There are a lot of parts and service companies to support the electronics industry -- it's easy to get prototype boards in you hands right away, for example. The sales reps for all the high tech test equipment will be wining and dining you, and demoing all their latest gadgets.
Where else to consider? Perhaps a smaller college town which has a good engineering school? Raleigh/Durham? Minneapolis/St. Paul? Austin, TX? Ithaca, NY? Champaign, IL? There are lots of similar places that have small concentrations of technically educated professionals.
Good luck, wherever you decide to locate!