Vibrations are always an issue, even more so on a new install. You should be fine but be sure to bring your tool set and a few extra nuts and bolts.
I'd stop periodically during the first leg of the trip at least to check up on things. The main motor mounts, exhaust studs, and believe it or not - the fuel tank mounts are all conspiring to loosen and even perhaps to abandon you! The list goes on...
Another key thing to look for is chain slack. It's worse if you have the stock chain that came with the kit as it's of low quality to say the least, but even a good chain will stretch a
lot while its new. With a new build on such a run, you may even need to pull a link after it stretches in - so don't forget a chain breaker tool and if yer clumsy like me - a spare master link couldn't hurt.
...and yes, I do bring just about everything I used to build my bike with me when I cruise heh, I'm just over a hundred miles on the thing and only now has it gotten to the point where I don't need constantly tweak it. I'll probably always bring 1/2 a hardware store with me though... Murphy and his damn law
Once it's all settled in trips like yours shouldn't be a problem, this forum if filled with people with hundreds/thousands of miles on their bikes - I envy every one lol One thing I did notice is a surprising amount of wear on the rear tire, I have a mountain bike with (cheap) knobbly tires though - I'll be replacing them with cruiser street tires and that should help.