I don’t think you could even get close to build something as good as what Pixieset or Shootproof offer. Even using the best RW stacks just scratches the surface and even if you could build it with stacks, you would need a great deal of time to build and debug it and keep it working.
You would need a sophisticated CMS solution, a sophisticated gallery and lightbox with user options, a remote multi client password protected client login area, email generation for mail shots and promotions based on birthday and wedding anniversary, a photo editing system and then a complex online shop with cart system linked to an in country fulfilment system linked to their changing prices and adjust for postage.
The best of these systems are very sophisticated and complex and there are huge teams behind them having already invested years into them.