bmilla:
No body has yet mentioned Miltonopsis hybrids. They love cool temps. East facing windows are just fine. They do not like a lot of temperature variance. I grow mine outside year round. Winter nights here drops down to 50F. But if night is low 60s and days upper 60s it would be ideal for these.
You can sometimes find these in florists or even home depot.
Here is a sample picture of one of mine that bloomed this summer.
Andrew