In Los Gatos, you have much more need for good central air conditioning than heating. With a good duct system in place, adding a furnace is trivial and not very expensive to buy or operate. You can put in radiant heating if you want but then you'll essentially have two HVAC systems.

Radiant heating in the Bay Area isn't all that common, especially not in Silicon Valley with our hot summers and very mild winters. As a result, really good radiant HVAC contractors are also not that numerous.

I know two people with radiant heating, both systems embedded in concrete slabs. One had a leak and the concrete had to be busted open to fix it, it was a mess. For the other, it works fine in the original part of the house but in an addition, a water to air heat exchanger was used to produce forced air heating and it works poorly. Both would change out their radiant systems if it weren't so expensive to do so.

Can you explain why you really want radiant heating?

Susan,

A forced air heating system doesn't create dust. If you have a good 4 inch media filter and change it regularly you should not have a dust problem. If there is any air borne dust the filter will collect it.

Forced air heating system also do not dry out the air. The major cause of low indoor humidity is outside air infiltration through leaky windows and doors. If you do have low humidity, a humidifier could be installed. In this case having a forced air system would be an advantage.