Diagonals of various formats (rounded up or down)...
135.............. 43mm
6x6cm.......... 80mm
6x7cm.......... 90mm
6x9cm.......... 100mm
6x12cm........ 125mm
3.25x4.25in... 130mm
4x5in........... 150mm
The only time you should ever consider using an enlarging lens longer than the diagonal of the film format is when making high magnification prints of greater than about 8x, IMO. This is because the lens is relatively far away from the film at lesser magnifications so only the center of the lens is used. As magnification increases, the lens is focused closer to the film so more of the lens' coverage is used. It's far more common to use a longer-than-normal lens for 135 because the enlarging magnification is much greater so 50-63mm lenses are the norm. By the time you get to 4x5in film you don't need to worry about using a longer-than normal lens until you get past a 40 inch wide print, again IMO. In fact, 135mm lenses for 4x5in enlarging are far more common than 150mm because few people print larger than 16x20in so the lens is far enough away from the film that the lens' coverage isn't being fully utilized.
So, IMO, I would go with the following focal lengths for 11x14 enlargements...
135.............. 50-63mm
6x6cm.......... 80mm
6x7cm.......... 90mm
6x9cm.......... 100-105mm
6x12cm........ 120-135mm
3.25x4.25in... 120-135mm
4x5in........... 135-150mm
But... since you can use a longer lens than needed, you could use the 100-105mm for 6x6cm, 6x7cm and 6x9cm. You'll need a 50mm for 135 (63mm is a bit long so enlarger height could be an issue). You can share a 135mm for 6x12cm, 3.25x4.25in and 4x5in. So, IMO, a three lens set as follows should fit your needs nicely.
50mm
100-105mm
135mm