Never thought i'd have to join the masses on here by saying what 'total and absolute rubbish' you have just written. I forgot as a PPL holder with no IR you can fly with mimimum vis and its safe enough to fly into CB's.
LA surrounded by mountains (mountain effect) and as with most of the west coast the weather does fluctuate (only on the coast) according to the time of day due to cold jet streams.
I recently finished CPL training at SFC and did what you are doing right now for a long time last year (trying to plan a successful trip in the USA). Through many hours of talking to these companies with very little confidence I did finally get a good feeling from my previous mentioned company and the experience was out of this world.
I can reluctantly agree with one fact pointed out by your other reply and that is, by the time you have paid for everything you won't have saved much money, however, what you will have saved is a great deal of time waiting for the weather to be good enough to get up in (Irish/UK weather) and with that taken into account you will end up saving money!
Please PM me if you would like to talk and i can also share pictures of aircraft and views if needed.