Well I knew sweet cherries are risky in Illinois. But if your in a risky area you need to plant cherries that have a higher probability of success like Black Tartarian, Whitegold, Blackgold, etc.
I also have interest in Duke cherries which are tart/sweet hybrids which I think have some promise for people like me which live in non-friendly sweet cherry areas. I have even thought about breeding Duke cherries since few are available and I think there is still room for improvement for Duke cherries. Here are some links to related threads.
Duke cherries
Duke cherries experiences? sources for trees/scionwood?
Breeding cherries
Breeding cherries
Dwarfing cherry rootstock