My appreciation of your aims at the moment is to save time cutting out from the blanks and getting the frame nearer to the finished shape than you get with a saw. There seems an awful lot of skilled hand working to get the product finished. On youtube there are a number of videos about CNC cutting wooden framed sunglasses and these look to be novelty rather than quality.

Sure, cutting out and pocketing the hinge recesses would save you a lot of time, but isn't your business based on hand-made quality rather than volume production?

On that basis, initially you would need a good quality small machine, maybe even as small as A5. If your business grew to the point where that machine was inadequate, then you would just get another one the same. That way if one broke down it would be an inconvenience not a disaster.