My eldest has only family name tradition, and that is to have the father's name as a middle name.
Ds2, got 2 middle names. His second middle name is Noel after my late grandfather, who passed 6 months after he was born.
However Noel was kind of a last minute decision after her was born, as his second middle name was going to be Sebastian. (This is our last)
I would go with whatever you feel comfortable with, and I don't think anyone will really mind. At least they shouldn't. I am sure there will be more children in the future.