2) Seal all intrusions of outside into the house-there's more than meets the eye
3) Forget brands
4) Have someone in that huge LA area do a load calculation on your abode-not rule of thumb stuff
5) Ask for references
6) Buy a higher end system that fits your budget-comfort is really nice
7) In the mean time, get on here and read read read.
8) Make the call when its time and don't look back