Barbara - Neither Cherry or Ipe. IF, however, by "cherry," you mean a wood sometimes called "Brazilian Cherry Wood," that is jatoba, and it is excellent. American cherry wood, however, is too soft. Ipe offers you problems of a different sort.
You've described yourself as being of smaller stature and used to a lighter bokken. Ipe is very heavy and hard. You'll possibly damage the bokken of the people you work out with. Furthermore, it feathers on impact - in other words, splinters of the wood grain lift off and tend to rip out and stick in your hands. And sanding won't make the problem disappear.
Kingfisher is a great place to go: their hickory bokuto are excellent, surprisingly light weight, yet very strong.
Ipe? Is that the same thing as Isu? This is an example of Isu just in case.
Is the Brazilian cherry heavy too? I'm guessing Japanese cherry wood is expensive and soft too? I'll look into kingfisher or I might go with the Isu, but i've not heard much about it, but if Ipe and Isu are the same thing then it's either white oak or hickory. Thank you thank you thank you.