2004 Honda Pilot

I am trying to make some changes to my vehicle's cruise control system (2004 Honda Pilot). More specifically, I would like to do the following:

-Once I get to a certain speed (say about 60 mph), I would like to disable downshifting (i.e., sometimes when a vehicle ascends a steep or long hill with cruise control turned on, the transmission downshifts; I would like to try to disable this downshifting).
-Also, I would like the cruise control system to signal the vehicle to slow down as it ascends a hill. More specifically, instead of increasing the throttle position while ascending a hill, I would like the cruise control system to hold the throttle position constant or decrease it during the vehicle's ascent.
-Finally, I would like the cruise control system to signal the vehicle to speed up as it descends a hill. More specifically, instead of decreasing the throttle position while descending a hill, I would like the cruise control system to hold the throttle position constant or increase it during the vehicle's descent.

Please let me know if you know how I can make any of these changes or if you know of any products that will help me make any of these changes.

Thanks for your help.