I had a similar application a while back transmitting the output of an accelerometer to a receiver 100' or so away. I guess the first thing I would ask is are you looking for a quick and dirty prototype for proff of concept or something that needs to be industrial grade right off? There are lots of suppliers but for a quick demo, I would look at the Microchip PIC type demo kits as they are pretty fast to get up and running. You could take the output from the pressure sensor to a simple A/D and then use that as an input byte to the transmitter. I'm not endorsing Microchip in any way but they offer decent application support and you may be able to get some help from some friends. Another thing I would look up is the wireless TPM or tire pressure monitoring system as you may be able to get something up there quickly.
If this is a more "mission critical" application, e.g. pressure sensor on a nuclear reactor (just kidding but you get the idea), you really need a more industrial strength solution with error correction, retry, fail safe code etc.