Justin isn't my favorite "J" name by any means but I like it many times more than
Jadon (however one chooses to spell it). Some male names beginning with "J" that I like include:
JeremiahJeremielJeremias JamesJob (though I think a nickname for this is entirely unnecessary)
JasonJeffreyJeffersonJoseph
The only problem I can see is that most of those have very well established nicknames already:
Joe for
Joseph,
Jeff for
Jeffrey, and so on. So just starting with a J might not be enough to convince someone that
Jay would make an optimal nickname.
Jason and
James, though, make sense to me.

www.qwantz.com