It depends what you call a "tour". Are you looking for a fast-paced ride, standing out of the saddle for major climbs and the like? Or are you looking for a more leasurely pace (not necessary slow, but not breaking too much of a sweat either).
Even if your "tours" are day rides or credit-card multi-day tours (i.e. you sleep at a hotel, rather than carry your tent), I would suggest you look for a "touring" or "cyclocross" bike. Both accept larger tires, and touring bikes have 45-46-cm chainstays (instead of 41-43 cm), which helps you to install panniers properly even if you have long feet.
As for tires, the narrowish road tires you saw will work for, maybe 2000-3000 km. But your rear end will break before that. I ride with 700x32 tires, and when I toured with a full camping load and a child on trailercycle, I used a 700x37 tire on the rear wheel. However, many of our roads and streets have bad pavement, so a bit of cushioning is helpful.
If you ride in Hawaii, I have no idea how the road surface is in terms of potholes, cracks, rough pavement, chip seal, etc. If your roads are as good as in Florida or Georgia (i.e. smooth as glass), you will be OK with 700x28 at 120 psi. Otherwise, go with 700x32 or even 700x37 (on both wheels or at least on the rear wheel).
Practically speaking, it rules out almost all bikes with sidepull brakes (aka caliper brakes), especially if you want fenders too, to stay clean when it rains. So you need a bike with cantilever or v-brakes.
As for bars, I prefer drop bars. Just make sure the fork remains uncut for a while until you finalise your positioning (they just put spacers on top of the stem – looks ugly, but it works). Install the bars at the same level or even higher than the saddle and use a short stem; that way, you will get all the advantages of drop bars (multiple positions, no wrist flex, more aerodynamic, etc.), but you won't be stretched out.