Ok... you've got a bunhc of different bikes that you are looking at, but they are all slightly different.
The Nashbar is your typical hybrid with flat handlebars and a very upright riding position
Then there's a 'light' mountain bike with front suspension and two roadbikes with 'bullhorn' handlebars.
So first question that needs to be asked is what *kind* of bike do you want. Based on your description of use, it sounds like you only plan on using this on paved streets and maybe the occasional hardpacked trail for short distances. If that's the case I would favor a bike with NO suspension. Why? Because bikes with suspension are less efficient, and this is especially true at the lower end.
Next is your riding position. Having a flat handlebar and relaxed geometry (more on that in a minute) allows you to be seated upright. People who don't ride a lot often prefer that, as initially its more comfortable. BUt it also is less aerodynamic and doesn't give you as many hand positions to switch around with as the bullhorns. In the end its personal choice - do you want to be seated more upright/natural, or do you want a bit more speed but leaning over your handbars more? I'd try both at a bike shop and see what you think.
Finally there's tire width - if you are truly talking about biking on paved roads nad paths you want skinnier tires which are much more efficient. If your path will take you on lots of dirt paths and/or if you think you might want to go riding up/down some hills than you'll want wider, knobbier tires (but it will be slower nad less efficient).
Final advice? Given you are looking at a whole range of bikes I think you need to go to a bike shop and just test-ride several bikes to see what feels good. Ask the sales-guy to let oyu ride a flat-bar hybrid. Then ask for a commuter-bike with bullhorn handlebars. You may decide not to buy from that shop, but often they'll have last-years' model or used bikes in their arsenal that they'll offer to sell to you. If you mention what price-point you've been looking at they might have an older model they'll match price on for you. And if you wondering if the price they offer is a good deal come back here and ask (preferably with pictures of the bike and/or detailed specs).