http://www.suspenzkayakstorage.com/f...g_storage_rack
Customer service was good. You can buy and extender to raise the boat up to either acccomdate a 3rd boat or lay a piece of play on the "U" for storage. Also, you can have heavy-duty casters for rollin' 'em out of the garage.
Along with free-standing units, they have arms you can use with wall studs. There's a good range of pix on their site for ideas for your own "strappage." Also, see some other threads here and at Hobiecat's main site forum.
Some yakkers have had good luck with slings/pulleys.