The person who runs the Eichler For Sale site sent me an email about their site. The site suffers from a needless use of flash (in fact, you can't even see the goddamn thing if you have flash disabled,) but is otherwise a good Modern (mid-20th century) home resource for your Northern California Eichler needs.
I like Eichlers, own the book and have had the good fortune to tour one of the homes down here in Orange. The one thing we noticed was that the homes, while looking totally awesome, suffer from a lot of functional obsolescence. The rooms are too small and the "flow" from room to room in some of the plans is just not practical.
I have found it helpful to do the stretching exercises my physical therapist recommends. Do some core strengthening exercises, such as the ones highlighted at The Mayo Clinic. By keeping your core strong, your back won't put itself in a position to cause that sciatica pain you are having.