If it were I, I would look at the following for the adults and pick any one based on aesthetics and price, as they all flush great:
Double Cyclone, Skirted, Universal Height: Carlyle II one-piece toilet (like an Ultramax II with a skirt) MS614114CEFG;
Vespin II two-piece toilet (like a Drake II with a skirt) CST474CEFG.
For more money, there are two stylish toilets that flush equally-great and also are skirted, one-piece, Double-Cyclone, Universal Height: the Eco Soiree MS964214CEFG and the Eco Guinevere MS974224CEFG. I think you go for those only if you are wowed by the aesthetics, as the first two I mentioned perform great.
For the kids, the lower toilet you probably want is the original Drake, which is not skirted, is regular height and flushes great. None of the double-cyclone toilets come in normal height, but the GMax 1.6gpf flush and the EMax 1.28gpf flush on the original Drake are legendary. Just a little less bowl-rinse than the double-cyclone. CST744S for the 1.6gpf and CST744E for the 1.28gpf.
If you want a skirted toilet for the kids, there is one at the regular height, but it's a dual-flush (i.e. push one button on it, get a smaller water usage to dispose of liquid only, push the other button when you have solids). It's also a washdown flush. (Washdown flush gives good bowl rinse.) That is, one of the several Toto Aquia dual-flush skirted toilets is available in regular height, with a washdown flush. It's a very popular toilet that people really like. CST416M in the two-piece.
Also, if you like a dual-flush at universal height, skirted, two-piece, the CST412MF is your Aquia. If you want it in a one-piece, it's CST654114MF. Again, the Aquias are very popular and flush great. But they are not double-cyclone.
If you want a dual-flush, skirted, double-cyclone, universal-height toilet, there is the Maris CST484CEMFG. Oddly enough, it doesn't come up promptly on the Toto web site (you have to go to "CalGreen Toilets" to find it), so I don't know if it is on the way out the door or not, but it appears still to be available at merchants.
Remember that all these toilets are available at a significant discount off of list price. You can look at Terry's prices above to get a sense of what's fair.