Sounds like you do not fully trust in the outcome of your luthier's endeavour. Most makers - big companies as well as small custom shops - will have a signature sound. Their sound may be affected by the choice of woods, but it will still typically sound like an instrument from brand X or luthier Y.
My personal approach would be to choose a builder according to samples of his work you like, not because he agrees to build something that will look similar to another brand. If you like the Pono ETSH, then why not just get that one? They do have their very own signature sound, so you'll know what you will be getting. Buying an instrument without holding and playing it takes a lot of confidence as it is when ordering from an online dealer, but it's even tougher to know the outcome of an instrument that hasn't even been made yet. Ordering from a custom luthier is always a jump in cold water, even more so with an unknown maker with little sound samples and reviews or known owners you could ask in confidence.
My personal approach would be to choose a builder according to samples of his work you like, not because he agrees to build something that will look similar to another brand. If you like the Pono ETSH, then why not just get that one? They do have their very own signature sound, so you'll know what you will be getting. Buying an instrument without holding and playing it takes a lot of confidence as it is when ordering from an online dealer, but it's even tougher to know the outcome of an instrument that hasn't even been made yet. Ordering from a custom luthier is always a jump in cold water, even more so with an unknown maker with little sound samples and reviews or known owners you could ask in confidence.