Whether you decide to buy online or not, make sure there is a dive shop in your area that services that brand. It will make your life much easier when it comes to repairs and replacement parts.
That said...actually buying some stuff from your local dive shop will help keep them open and available to serve you. I get things from the shops as well as online. Wetsuits are good to get at the shop so you can try them out and get the best fit. ScubaPro also has lifetime parts and service on their gear. I’ve got some of their regs and it’s nice to know I can take my stuff into the shop whenever I want.