Have to agree with doing the kitchen first :)

We ran into the same issue when kids were small and did our basement as well. It added tremendous square footage to our living / storage space, and we lined the basement perimeter with cabinetry and added a crafts center (the pull out table cabinet was awesome we used the table cabinet in the second row of pics here in this gallery ). We even had one cabinet dedicated to birthday party gifts and wrapping. If cabinetry isn't in the budget for the basement, you can find really nice stainless steel shelving that would work as well for overflow storage.

Congrats on your new home!