I hate to be the odd ball here but I disagree with smoking chicken at a higher temp. I typically run leg quarters at around 225-ish for 5 hours. Keep in mind that for the last little while I put them skin side down at a higher heat zone (maybe 300 or 325). It always comes out fall-off-the-bone tender. I don't bother with a brine because it's hard to duplicate conditions on a consistent basis when it comes to brining (at least for me).
Since you're only doing small thighs, I'd estimate 3.5 hours or so at 225 to 250. This is only an estimate and should be checked with a therm. I'd let the thighs cruise at 225 for at least 2 hours then check the temp. Once it gets within about 10 degrees, flip 'em over and feed them more heat to brown up the skin and finish cooking. It'll be damned tender.
Either way, don't forget the QVIEW!,