Buying bike for trans Canadian journey and possibly more in the future

I'm looking for a bike that will take me from Vancouver to St Johns this summer. I plan to stick mostly to paved roads but I will want a bike that can handle a bit of dirt too. So I'm thinking strictly road bikes are out of the question. But I also want to develope a relationship with my bike. Bring it with me to Europe or Africa or wherever I may go and ride it there too.

Im just not sure what to get. I'd like to be able to buy a $1500 bike but not sure I can justify it yet. Im sure that a well crafted $300-500 bike will do just fine. What I really have my eye on is a Giant Sedona. It is $420 CAD which seems to be fair given the name and the quality that this bike has. I've read numerous reviews about long journeys in this bike. Will it suit me for a cross country trip with probably 99.5% pavement? Or will it slow me down too much compared with a road bike? Is the front shock just a matter of preference? Is there any reason for me to switch up to a Sedona DX?

I've also been looking at Diamondback bikes. As these two brands are the only ones sold locally. I want to keep it local. They seem like good bikes and have a model that would seem to work for me. Diamondback Transporter which seems nice. Much like the Giant Transend but just a lot cheaper. Has splash guards and a rear rack included. Not sure if these will assist me or just hinder the performance of the bike?

If anyone can suggest another bike or just generally assist me in any way, I would be greatful. Thanks.