Where to find fabric for a boy?

I'm planning to make the August Fields pieced duvet cover from the online pattern by Amy Butler.  I need to find good fabric for a boys' room--I want it to be more geometric/abstract so that it's not babyish (he's 3 now, I want this duvet to last!).  The pattern calls for using 19 different patterned fabrics plus 2 coordinating solids--I can survive not using quite that variety (maybe 8-10 patterns).  Any recommendations on fabric collections/stores?

Of course I think our store has a great collection of boy prints. Here are some of my favorites:
Hope Valley
Kaffe Collective & his Shot Cottons
Spa

You might also search by color or print. It might help you narrow down some choices.