Love it. I don't know about similar length and flow, but here are a few suggestions of similar popularity:
Rex,
Max,
Felix,
Linus,
Rhys,
Clement,
Dominic,
Julian,
Peter /
Piers,
Damian,
Adrian,
Sebastian,
Vincent,
Mark,
Hugh,
Jasper,
Nicodemus,
Francis,
Martin,
Quentin,
Xavier,
Aloysius,
Ignatius /
Inigo,
Milo,
Ivo,
Hugo,
Terence,
Malcolm,
Ian,
Eli,
Patrick,
Desmond,
Henry,
Alec,
Bernard,
Benedict,
Ulysses,
August /
Augustus /
Augustine,
Stephen,
James,
Alistair,
Rupert,
Laurence,
Gerard,
Thaddeus,
Paul,
Jude,
Oliver,
Bartholomew,
Matthias,
Elias,
Tobias,
Wolfram /
Wolfe,
Phineas,
Oscar,
Gareth,
Owen,
Evan,
Rory,
Finn,
Kurt,
Cornelius,
Gervase,
Roland,
Simon,
John,
Gabriel,
Josiah,
Thomas,
Edward,
Noel,
Barnaby,
Cary.