Hope this is a fun process for you. I second the idea to narrow your options based on what your room is used for--and kid-friendliness. Another consideration is the kind of look you want--in other words, do they dominate the space or do they also fit in with what else is around. And, simply, do you like the way they look?
If I were buying a speaker for your size of room, at your budget and assuming it's also used for other things, I'd buy the Harbeth 40.2s. But that's just me--there are many good choices depending on what you like and the needs of your family.