> First I thought I would use 12vdc, and use a hefty wall wart.  But here
> you end up needing up to 3 or 4 amps.  And this I don't quite see how
> you could do on a circuit board.  Yes/no ??

Yes

> Oh yeah, I want it to be very small and compact to fit in a little box
> on top of the valve.

A conventional transformer supply for 4A would be quite large.
Even a switchmode could be fairly large and possibly troublesome
to make and test if you've little experience

> The 110 vac valves seem to use very little amps.  So maybe this
> is more appropriate

It does mean that you'd need no components at all to get a supply
for them, as it's already there at the wall

>  But how do you mix ac from the wall and 5vdc for the pic?
> I guess I need a power supply

And an opto-coupler + triac as the interface

> I would like to have something that I can plug into the wall that will
> give me 110 vac for the valve and 5vdc for my pic.

http://home.clear.net.nz/pages/joecolquitt/txless.html

Be careful !!!!!!!  And be aware of any electrical regulations that
may apply

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