I love
Finnegan. It's my favourite full name for
Finn, except for
Fionnbharr, but that's not practical. I like
Phineas too (this spelling) but not as much as
Finnegan if you're going to use
Finn. I think I like
Finley better than
Finlay. If you're going to use an Anglicized version might as well make it as straightforward as possible.