hello SoCal riders. i'm planning to visit some friends in the LA/Irvine/Laguna Beach area (maybe as far south as San Diego) and will be bringing my road bike. driving down from the bay area. would love to hit some climbs along the way and see what's around while i'm there. from reading a few posts here it seems GMR/GRR and 39 would be a good start. what else is on the must do list? hoping some locals could point me in the right direction

basically...

don't mind driving a bit for a good ride, i am taking a road trip after all.
prefer long climbs with lots of elevation gain (i <3 steep too)
low traffic would be best of course but i can ride weekdays if that helps.
water stops?
where to park?
what to avoid?