Digikey has a range. For the High Pressure side of the system you might consider
http://search.digikey.com/scripts/Dk...me=223-1014-ND for about $130
While for the low pressure side something like this
http://search.digikey.com/scripts/Dk...me=480-1922-ND might be more affordable. $25 or so.
I would do a careful search, however, of all the pressure transducers available on digikey, and take care to read their data sheets. I've just picked these two out as possible examples and HAVE NOT confirmed either that they would be FRC legal (whether you care or not...) or otherwise a good choice for your application.
Jason