I've been printing 120 panoramics for years using a stretched 4x5 enlarger. The enlarger will handle a 4 x 14 neg and has a colour head. Most of my negs are around 12 inches in length.
What do you mean by "stretched 4x5 enlarger"? When you say 4x14, do you mean centimeters? How can you print 12-inch long negs when even 8x10 enlargers only go to 10 inches?