When I first started my day home my plan was to have all the same age kids, around a year. I figured it would make plans/activities easier since everyone would be the same age. Now that I have been up an running for a few months, I'm glad I didn't decide to do that. The three kids under 2 that I have (10 mths (my own,) 15 mths and 17 mths) are a handfull and I have three just over 2 (2 (my own) 2 1/2, 3 1/2) as well. My days seem to consist of preparing food, clean up and a lot of bum changes! It does get easier but I have now decided that I will never have more than one non-walker in my care. Even getting out in the yard can be a chore sometimes since I have stairs down the back patio.
I even had to turn down a woman and her one year old, after I already got her to sign a contract and pay a deposit. I felt bad doing it but I knew for my own sanity and the safety of all the children, I couldn't take on another younger one.
I think there are going to be stressful days no matter what ages you have (trust me, I have had many) but you have to go with what you're comfortable with.