Shipping to Mexico is notoriously unreliable even if you use a major carrier (FedEx, UPS, etc) and customs can/will hold stuff. I recall reading about a Mexico bride who shipped her dress, and it never arrived at the resort. Unless you're willing to take the chance that your items are never delivered to the resort, I wouldn't recommend it. I'd spread them out in suitcases, or plastic bins, and enlist some of your closest family & friends to help you by taking the goodies down with them. Are there items you could potentially purchase in Mexico, and avoid carrying them with you. OOT bags are one of those things that are a really great idea, until it comes to the logistics of carting stuff down and stuffing the bags. Especially for a larger destination wedding... good luck to you!