It depends on what setup you are using If using wordpress you will want to have a good platform, I use eShop. You could go with woocommerce, or a variety of others. As long as the system you are using allows for customization easily you should be good. I think wordpress is the way to go, but a good PHP guy can build a great e commerce site too. Have reliable ways to pay, have shipping charts, it gets a bit hectic buiding a site like this but the end result can be profitable
You can look regionally for web designers, browse the on the internet google or publish a job information at an website like Expert.com or Getafreelancer.com for local or nationwide applicants. Whether you're looking for a short-term independent designer or a full-time source person to be a part of your team, don't believe in your internet business to the words on a candidate's continue. E-commerce, in particular, can need a higher level of technological encounter and information to set it up and, in some situations, to sustain it. A good developer can go a lengthy way towards simplifying the procedure for the end customer.