You're right on about bonsai - live oaks are used, but don't bring it inside, it will not be good for it (unless you're in a cold zone). Double check if they normally live in 7a through the winter.

Sarah,
Go ahead and plant it. It will survive; though I can't swear that it won't occasionally incur some winter damage. There is a live oak growing here in southern KY on the campus of the community college, across from my office, planted in 1970. I've never noticed any winter damage, and it produces acorns on a regular basis.
GW member rhizo1's husband used to have one growing in the backyard of a house he lived in in Huntsville - he sent me photos of it, and it looked just fine.
I've got a couple of seedling live oaks in my nursery beds here - grown from acorns I collected on the Auburn University campus about 6-7 years ago. They're doing OK, but some years, they get some 'freezer-burn' on the leaves.

Hey there, Cuz'n Lucky! Robert and I drove past that house this weekend and the tree is still there and doing fine. I couldn't believe how much it had grown! There are several Live Oaks in Huntsville, according to our retired City forester.

alright, thanks everybody! in ground it is.

They grow fast too. I picked up an acorn at a rest stop in Louisiana last fall and planted it. It is 3ft tall in just one year.

Hey sweet thang(rhizo)! I figured you'd be by to comment eventually.
I was thinking about y'all over the holiday weekend. I've gotta make time to stop by & see y'all sometime on one of my runs home to Auburn & Wetumpka.

I've got one little Q.fusiformis(TX/Escarpment live oak) seedling in a pot, from acorns sent by our KS friend kman04 - gotta get that baby in the ground somewhere, if only just sinking it pot and all, for the winter.
I'm not so sure but that the community college tree may be Q.fusiformis, which tends to be a bit more cold-hardy than Q.virginiana, and this one is growing as a 'copse' - a clump of 10-12 main stems all radiating from a common central source - also a fairly common feature for Q.fusiformis, though it could just indicate a freeze-to-the-ground event or being run over by the mowing crew early on. Tree is not a whole lot more than 15 ft tall, after 37 years in the ground - but no evidence of winter damage in the 8-10 years I've been watching it.

Good luck! If those don't work out you could try Laurel Oaks (Quercus laurifolia). The leaves are simple, alternately arranged, and may persist on the tree until gradually falling in early spring.