Felix, Sebastian, Zachary...opinions and suggestions please

Sorry don't

I wouldn't use Joseph or Sebastian if you son like Joe or Seb/Basty. I personally don't like either of them either.

Joss is much nicer, but I'd probably use Josiah or Jocelyn.

I love Joss for a boy, I think it’s fine on its own or short for Joseph (or Josiah) given Jocelyn seems to be now seen as a female name only. If you call him Joss from the get go I don’t think it’s likely it will turn into Joe

I also really like Zachary

Max is nice but way overdone

I fine Sebastian and Felix a bit fussy, and Joss and Zachary are more unusual too.

Xavier (Xav)
Laurence (Laurie)
Abraham (Bram)
Dominic / Nicholas (Nico)
Augustus (Gus
Ignatius (Iggy)
Alistair
Tobias
Dashiell
Tristram
Guy
Saul

might be others

I have a Zachary who is 10. There's one or two that I know but he's always been complimented on his name. He loves it. Felix has always reminded me of a cat.
Love Max and Reuben

I'd go for Felix. The whole shortlist is good, and I also don't like Seb or Joe.

Other suggestions:
Tristan
Patrick
Finn
Otto
Magnus
Caspar
Stefan
Robin

Sebastian is my favourite- I love Seb for short though, but wouldn’t use if I didn’t.

I also love Zach and Max.

Felix is nice too - if your friend doesn’t mind, this sounds like your favourite?

Joss I’ve only heard as short for Jocelyn, so sounds feminine to me, but it could grow on me. Josiah as mentioned above is a nice longer name if you wanted Joss.

How about

Jonah
Isaac
Casper
Jasper
Finn / Finley
Nathaniel / Nathan
Luke
Dexter
Rex
Lewis
Elijah / Elias / Eli
Dominic
Reuben
Joel
Ezra
Toby
Evan

I found it hard to vote as I seem to be the opposite to you when it comes to nicknames. I love Joseph nn Joe, but really dislike Joss. I'm not keen on Sebastian as a full name, but I love Seb which is super cool.

I voted for Zach in the end as Zachary is ok as a full name and I quite like the shortening of Zach too, but I do prefer Seb and Joe. Max is ok but not a particular favourite of mine.

I'm not a fan of Felix. It depends how close your friend is, but personally I wouldn't use it despite the age gap between the boys. It just seems to lack imagination a bit to use exactly the same name as a close friend (assuming they are a close friend), no matter how much you love it. I've never been one to be bothered about name popularity, or one to think children need 'unique' names, but I can't imagine using exactly the same name someone close to me has already used.

I can't see any voting options unfortunately (using the app)

The problem with Sebastian is the lack of good shortenings. Seb/Sebby is awful (and reminiscent of sebaceous) and Basty sounds too much like Bastard...

Felix is ok but a well known brand of cat food in the UK

I really like Joss! It's a great underused name.

How about

Caspar
Quentin
Magnus

I voted for Max, but I also really like Zachary.

I don’t dislike Felix and Sebastian, but I’m not particularly keen on them. They have a kind of cultivated-upper-middle-class vibe for me.

I’ve not heard of Joss as a boys name, but I quite like it I think.

I know a Joss short for Jossiah

I like them all, but Sebastion would be my favourite.

Have you considered;
Phineas (Fin)
Ezekiel (Zeek)