this is the exact same issue I had with my TJ last month, smoke and all.
it was indeed a sticking front brake caliper. took it to my local Jeep dealer and he pulled it apart and showed me how all my front brake hardware was original and in bad shape. I needed rotors, calipers, pads and the soft brake lines. Total cost parts (all Mopar no aftermarket) and labor was about $700.
2002 Wrangler Sahara, all stock, 5-speed, Dana 44, duel tan tops, 2nd owner.
2008 Hemi Grand Cherokee Limited 4X4, Quadradrive II, original owner, 22,000 miles.