David,
Not really a what to on here, you need to work out what you system is going to be doing, what are the various power rail requirements and current consumptions, do you have DRAM, are you using USB ports, etc, Vybrid itself was designed to run from a single power rail, under certain circumstances, so a PMIC is no required, a discrete solution could be used, but you should consider your overall system requirements, then probably makes more sense to discuss this with the likes of Linear and Maxim, who should be better suited to help you narrow your search.
Our TWR board uses a discrete solution, we are looking at using Maxim's MAX16993 on another project, but this is just a reference for you, this is a good fit for what we are doing, but whether of use to you depends on your system requirements, but I would recommend establishing your requirements and then discussing with the PMIC manufacturers themselves.
Ross