Nah, go local. Get the phonebook (lots less crap than Google these days) and find a local shop that sells hardwood and tools to woodworkers. Most of those places will have a shop where they will cut wood to your specifications for something like $35 an hour or $2 per cut. Don't worry, four sides and a base shouldn't require more than $20 of labor.
You'll also get to pick over a huge amount of lumber on site. You might be interested in oak or maple now, but just wait until you see another 60 or 70 species of wood. You'll probably change your mind.
If the store doesn't have a shop on site, check out their bulletin board. There should be a mess of woodworkers looking for small projects to build. If not, then put up your own ad asking for help. You'll find someone, for sure.
Also be sure to ask them about design and finishing. Joinery, while not tricky, isn't something you know about unless you've worked with it a bit. Same with finishing. Don't just buy a can of something, ask for an opinion based on the wood you choose.
