it'd be easier to buy a valve with the coil. like this:
http://cgi.ebay.co.uk/5-port-solenoid-v ... 500wt_1156

this valve would work if you are going to be running of 24v. or you could buy one new from:
http://cgi.ebay.co.uk/Pneumatic-Solenoi ... 797wt_1141

i bought a 24v 3/8 valve from this seller. all seems good.