The best quality I got from panoramics taken with the Noblex 135 S (24 x 66mm) were scanned on a Nikon Coolscan 4000 (now upgraded to the Nikon Coolscan 5000). I had to scan them in two pieces, as the Coolscan only allows 24 x 36mm, but you then have enough overlap in both picture halves to do a perfect stitching. Stitching in Photoshop is quite straightforward, but it is time consuming as well.
I also used a basic software made by Canon with a stitch option, results were surprisingly good. It also corrects for slight colour nuances between the two picture halves. Alas, I don't recall the Canon software's name.
I haven't tried a flatbed scanner, but it seems to be the easiest solution.