I own a Canyon Endurace and I love it, butsince this would be your FIRST road bike, AND because you're outside the norm at 6'4", I would discourage you from buying one. When I bought mine, I already had 10s of thousands of miles under my belt, and three bikes with fit very well for measurement and comparison. I have worked on my own bikes for years. Both of those things meant I could readily determine which size would fit me, AND I could feel confident in my ability to put it together when it arrived. Canyon's model works pretty well for more experienced cyclists, especially those within the normal range of size.
Others have suggested a bike fit, but my take on that is that until you've ridden a road bike for a few hundred miles at least, your form is not settled.
SO, my suggestion is to get a bike you can ride. That is, a bike that's available for you to ride before purchase. Work with a shop to get the size that should work, have them set it up, and just ride. As your mileage increases, take note of pain/soreness/numbness issues and after a while take the bike in for a more complete fit, with your list of issues.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles