I use option 1. then correct the whole pano if necessary, including tonal changes, all preferably in 16bit.
Finally after a test print, reduce to 8bit to keep the file size down.
I've never yet done a 3-exposure HDR pano, but that's because the sun has never been in the picture - this is probably the nearest http://www.berrisconolly.com/photo_7044243.html
but single exposures presented no problems (there's a touch of sun through early-morning mist on the left).
One thing to remember is clipped highlights are easier to recover than shadows, when using RAW.