You could have two middle names..

Jett Melvin Levi
or
Jett Levi Melvin

Both sound great and I like the sound of Melvin with Jett anyway! You could compromise on the middle names - DH can have his father's name for this bub and the next bub can have names from your family.

Suggestions for boys and girls....

BOYS

Jasper
Finley (Finn)
Quinlin (Quinn)
Blake
Drake

GIRLS

Harper
Addison
Violet
Malia
Allegra