Oops... Never seen such things as a OEM module. Usually it is pretty expensive instruments that have some other functions as well.
Looks like you have to design it yourself or order a custom design from someone.
BTW (to gurus) - is it possible to use doppler direction finder tecniques for this stuff? As I understand, all that is necessary is direction to a transmitter, am I right? If yes, DDF will give MUCH faster result than a rotating horn antenna (but sensitivity is a question).