I posted in this section of the forum because of the frequency, if it should be somewhere else it can be moved.

 1.  An ADS-B receiver in the physical form of a USB GPS mouse (receiver) would be ideal, maybe in another 10 years.

2.  Next best solution would be to tweak the frequency of the GPS receiver
L1 (1575.42 MHz)
L2 (1227.60 MHz)
L5 (1176.45 MHz)
to 1090 MHz and reprogram the micro controller.  Maybe near impossible without replacing the chip/etc.

3.  Getting the module made by Sirf, MTK or whoever.  Initial cost would be prohibitive but for the anticipated long term need it may still be viable.

4.  The miniadsb receiver project by vinculum looks very promising, the need for an extra microcontroller (PIC/AVR) and the time required is a major drawback.  It could be done but I have not used my scope in several years.

 So the question I have for those that have worked in this frequency range and possibly worked with mode-s/ADS-B for an anticipated short term need of 100 units is there a suggested path to take.