FOUR 29-inch bags for 2 wks in Fla. in Aug? Yikes! I'm using one 29 in. (for 3 people) for 2 weeks in N. Europe at the end of March!
If you want to get your kids luggage so that they will have luggage, that's one thing, but so they won't fight over sharing? Bad idea. Any seasoned traveller will tell you that it is not a good idea to segregate individual cases for travelling companions. You should mix clothing for the whole party into each case, so that if one or more cases get lost, their owners will not be stranded without clothing. When you arrive, assign a drawer to each person, unpack the cases into the drawers, and then put the dirties back into the cases as you go. You're already packed when you're ready to leave.
Big duffels are fine, but do get the wheeled sort, with the in-line skate wheels, definitely, much easier to transport. 29's are a bit on the large side for what the avg. young male would normally use, though, they tend to be sparing with stuff when they travel.
Be careful about the weight of the bags themselves, airlines have gotten much pickier about overweight charges, so go with the lightest fabric you can.
Don't lock with locks. Zip ties or twisty ties are good for soft bags to be sure that the zippers stay shut, but don't waste your money on locks, b/c all ads to the contrary, TSA *will* cut them off. As for the extra bag for souvies, my advice would be to pack a flattened cardboard box instead, along with a roll of package tape (with a tear edge) in the checked luggage. If you buy breakables, have the shop give you packing materials for them. The business center at your resort can send the package home for you, as insured as you want it to be. (If you have access to a UPS or FedEx account, bring along a coded waybill, too. My office lets me use theirs, and when the bill comes, I just reimburse the co. for the shipping charge.) Of course, you can always have the shops at WDW sent things directly home for you.
