You've asked for custom made Magic Sleeves that can accommodate up to a 12.9" iPad Pro or a 14" MacBook Pro in a regular orientation (not a duo style sleeve). I'm making these "combi" sleeves at my home studio in small batches. With that flexibility, it also enables offering a matching felt handle as an option. 

The combi size is a very flexible Magic Sleeve, with the ability to fit an iPad or a MacBook— or both. 

magic sleeve combi
outside (open) 22.75 x 14.75" (57.8 x 37.47)
outside (closed) 11.4 x 14.75" (28.96 x 37.47 cm)
inside (usable) 9.75 x 12.75" (24.77 x 32.39 cm)
- fits up to a 12.9" iPad Pro (with Magic Keyboard and pencil attached) and a 14" MacBook Pro.