Depending on the urgency of the need. I use the forums, Frag SWAPs, local pet stores, eBay, facebook market place, etc for used equipment. For new I use Cincinnati Corals, Bulk Reef Supply, Saltwater Aquarium, etc. For life critters I use Cincinnati Coral (treated/quarantined fish), Live Aquaria, Aquarium Depot, etc.
I hope this helps. There are a number of members that can really help out too.
Gary