From what you suggested, I
LOVE Brady James,
Brady Tyler, and
Brady Grayson. The only issue with
Brady Grayson is maybe the Bray- and
Gray- sounds are too similar/rhyme-y. Also, while
Michael isn't my FAVORITE name, I think
Brady Michael flows well. Honestly, I don't think the initials between the first name and middle name matter AT ALL. I think that the initials between the first and last name are much more important, and the intials of all three names together. But most kids don't even know each other's middle names, and they never go by their middle name at school - it's usually just used by parents/grandparents, on formal documents, or when they're in trouble :)
So in a way, yes I do think you are being too concerned about the relationship between first and middle initials. Especially with the letter "C" and "K" - BCN and BKN doesn't spell anything weird, and I would never think Bacon.
Also, for the length,
Brady is a pretty short name. Two syllables and 5 letters is really not long at all. Your last name is also relatively short. There are SO many people with much longer last names.
Brady Nething is very average in length, if not on the shorter side, so I wouldn't worry about that.
I do want to say that I
LOVE the name
Brady. It's in my top 5.
Some other suggestions:
Brady LucasBrady ColeBrady CarsonBrady ElijahBrady HoldenBrady KyleBrady LoganBrady OwenBrady OliverBrady PaxtonBrady RyanBrady ThomasBrady WyattBrady AlexanderBrady GrahamGrady Grant