The one thing I have notices regarding care for 2 and up is...it's limited. Generally a child at the age of 2 yr with working parents has already been placed in day care. The only way you will get 2 yr old is if they are leaving another care facility (which can be a red flag) or the Mother is going to work for the first time, (which can also be a bit of a hurdle) best bet really is to start with a younger child newborn to 1 yr, and work your way with them to the preschool level. Think about it, if you start with them when they are young, they will grow with you, and you them. They will be easier to "mold" rather than having to fix bad habits, you can set solid structure from the get go! If you want to wait out for 2 and up, your search will take twice as long given the fewer in that age specific group.
Having children of all ages definitely poses more stressors on the daily schedule and activities such as preschool and outdoor play, but if you broaden your horizons and take on children a little younger, you really could find a nice group of 6-12 month olds that will be ready for preschool in another few years, but the trade of 2-3 years worth secured income is well worth the wait!