There is still no commercially-available equipment for the 902 MHz amateur
band that I am aware of.

Using commercially-available equipment is cheating anyway. What does it
take to modify PCS cellular phone firmware for digital communication on
902? Is it just a matter of firmware or isn't the RF section able to tune
that far out of band?

Think of it this way. When you have an FM broadcast antenna and transmitter, it
makes quite a difference when switching within the same band from 88 Mhz to 100
Mhz. (only 12 Mhz)

Now you want to take something from around 850 Mhz to 902 Mhz (52 Mhz
difference)

Plus the higher up you go, the more critical the circuitry. Even in the 440
band you are already dealing with microsurgery when using the miniature surface
mount components.

Besides, working with microwaves is never a good idea. Might as well just take
up smoking cigarettes instead.

I would play with mercury and use lead paint in my home no problem, but I would
not ever build a transmitter and use microwave frequencies.