Without breaking the bank (though this model type can be pricey so shop around), I would suggest looking into the P7100 series as an option. They are offered in all three bands you are looking into, and programmable by ProGrammer Software from M/A Com (now Harris Corp.). Be aware though that the UHF band comes in two different sub-band splits, so keep that in mind as you do your research.
And yes, an 800 MHz EDACS trunking capable radio can be programmed as receive mode only, but it depends if it's ESK (a security key that is loaded into a radio prior to registering on the TRS to thwart unauthorized radios from transmitting and monitoring). If that is the case, then you will need to have that key programmed by the system administrator. If the system uses Extended Addressing (such as the Cecil County, MD TRS), then there is another obstacle to overcome that I am not familiar with. Otherwise, you should be ok for monitor only, as I do everyday on my local County system. You would also have to look at each radio and determine what the specific Features are in the radio (found in the Menu section in the radio itself), which can be defined from this Forum by searching for the Updated Features List by M/A Com (now Harris Corp.)
As far as your VHF digital situation goes, which type of digital are you looking at: Aegis, ProVoice, or P25? You could get all three in one radio, but be prepared to pay a bit of a higher price. Aegis (feature code 12) is the oldest of the three currently offered. ProVoice (feature code 29) is the most common form of digital used on the M/A Com / Harris radio line (though being replaced by P25 gradually in the near future). And P25 (feature code 33 for conventional mode; 39 for trunking mode) can be found in this radio model as well. Narrowband mode for all of the radios will be found if feature/option 23 is installed.
Others that know more than I will contribute to your search (and/or correct any of my statements) for the best possible choice of model types.