hi, I live in Sunnyvale and did my seemandam in my 6th month in October and it was really cold. As we live in an apartment and the guest list was above 30, we did the Seemantham in a hall in Milpitas and catered the food. However this tired me out as the preparations were too many. Most of my friends do the following 2 ways
a) Livermore temple - You have to pay the temple for the space and the Priest. Comes out to about $200, get the food from home and it can be buffet eating at the temple grounds
b) Conduct it at home :You will need to pay the priest for coming and Transit charges too.A few of my friends catered from Komala Vilas and Bheema's for $10- $15 a plate. Worked out simpler
The ceremony is pretty consistent with Indian ceremony, as you can get most items in the local Indian stores.
hope this helps