I have the Nano and it's great ... so long as you really, really mean to restrict yourself to four or five pedals, or if you're happy routinely re-building/re-configuring your board between gigs.
If you can't be sure about that, you'll need something bigger.
Power supply? Easy ... check out the Diago Powerstation. Great product, and it's British, and they do excellent customer service & backup.
Flight cases seem like a great idea until you have to lug one in and out of gigs. The flightcase will routinely weigh four or five times as much as the fully-loaded board. The empty flightcase is also a bloody nuisance at gigs.
There are some very good pedal board + protective cover things out there, and the pedals themselves only really need protection from rain ... they're designed to be stamped on!