i know how you feel and i was so over searching baby names with my last pregnancy it really did my head in!
ds1 is Nixon Milton so both end in "ON" but we very rarely use both of his names so in regards to worrying how Griffin sounds with the middle name if its not a name you will use much does it matter a while heap? (to us the name Milton was more important than how it sounded because we wanted a family name incorporated in his name)
I like Griffin, ds1 went to preschool with a Griffin and although i have heard the name tossed around a bit more i still only know of the one Griffin.
Kaelan was also on our list we liked Kale but didnt sound right with our surname but Kaelan did.
i see Divvy already suggested it and ofcourse i am biased but ds3 name is Ryker and i love it. we only decided on it 2 days before he was born. We get lots of lovely comments on his name and surprisingly mostly from older people!!
Kyan and Kade i also like but a little more popular now.
i think Tyr would be forever getting Ty instead of Teer? ds2 is Tyron and he gets Ty for short.

good luck its tough when a name doesnt just come to you but Ryker took time for us to love it was on our list for 3-4 months but wasnt at the top of the list, now i couldnt imagine using any other name for him