I know someone named Carden so it doesn't sound strange to me. I think it flows well with your son's name and your last name. Just glancing at your list, I thought some of those were definitely too popular to use with the awesome Aiven- Conner, Weston, Braydon, Grayson, etc. I say use Carden if you really like it. It just goes well with everything else :)
Never heard this one before, but I think Aiven and Carden are great together!
I like Carden, I think it's nice and unique.
I also like Connor and Rylan from your list