+1 on "What Jon Says" (tm)
World of Strings is your best bet - it's easy to get to - from Torrance take the 405 South , 710 South, 6th street exit (East), merge with 7th street and it's a couple blocks on the right.
Nice place, great people and a good selection of basses. Leave yourself some time to play them - I'll probably be there Friday checking some out myself.
On the other hand, I never buy strings from shops - it is way more cost effective and convenient to buy online. I mostly use
Quinns - good prices and service, although it does take about a week for them to get strings to me.
Good luck,