>>#1 NEVER get a wild box turtle.
I have 2 wild caught box turtles. Some people are successful with them.
And plus you don't want to deplete the wild populations.
It's possible to buy CB only 1 step removed from wild-caught (i.e. parents wild-caught), but if it makes a person feel better... 
>>#2 Wood should work fine with an outdoor pen. It works for me!
Keep in mind though that box turtles, especially ornates, can climb very well--even vertical surfaces provided there are sufficient toe-holds. Be sure you design and build your pen carefully--maybe even with an inward overhang at the top to safeguard against escapes.
>>#3 If you want to start with babies then don't even think about moving them outside for at least another 1 to 2 yrs.
What is the basis for that? Wild babies do just fine, apart from predation, and a lid on the pen will prevent that.
>>#4 I heard some where that the laws were VERY tight about box turtles in Kentucy. It was something like you can't own anything that is native to there or something weird!!
There are quite a few states like that. California has some pretty idiotic laws regarding herps, though I don't think they're enforced (e.g. I'm sure they don't tell you at the pet store you need a fishing license to legally own a captive-bred Cal king). Many states have laws against keeping native animals, but it's OK to bulldoze all the habitat to make more houses. 
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Chris McMartin
www.mcmartinville.com
I'm Not a Herpetologist, but I Play One on the Internet