Hmmm... can't say I've ever knowingly smoked with any of those woods. Most smoking pros will tell you that hickory is the way to go. Personally, I prefer mesquite and pecan. Just about any fruit tree works out very well (apple, cherry, etc.), but they are typically hard to find and/or expensive. The main thing you want to do is be sure to stay away from any of the bitter/strong woods like pine and pinion... smells great, but from what I hear, and logic would say as much, the meat will taste like crap.
Once I got Smokenstein up and running, I found that I was going to need a ton of wood to keep it running. I bought a half rick of pecan, and a full rick of "firewood"... which was basically a mix of whatever they had, probably mostly oak and hickory and God knows what else. I've found that oak works fine, so if you can't find hickory, pecan, or the other woods mentioned above, that should do.
Most importantly, make sure you are using well-seasoned wood. Nothing makes your meat taste more bitter than using green wood.
Depending on how your smoker is set up, and how big it is, you should be able to find your basic smoking woods (Mesquite, Hickory, and Pecan) in chunks at your local Wal-mart or other grocery stores... but it sounds like you'll have too big of a smoker for that. If not though, you can always mix some of these in with charcoal to save on the amount of wood you will need. Mine burns like a fireplace, so coal is out of the question or I'd go through an entire 10 lb. bag easy in one smoking... but in my smaller smoker, I would mix coal with wood.
Hope this helps. Good luck with getting the smoker built. And can't wait to see it! I love seeing custom made smokers.