Out of your suggestions I'd have to say that Rowan would be my pick. It's not too common, and i think its a name that would grow on me with time.
Ewan- sorry, but i just can't get past the similarity of the 'eww' expression- (written, that is). Verbally i don't mind the name. I just think it needs to be spelled differently somehow- Yuan, or something.....
Denzel- again, just can't get past Denzel Washington. He's too famous for me- IYKWIM? Having said that, I loved Ashton for our son and my hubby wouldn't accept because of Ashton Kutcher (damn those celebrities!!). Denzel is a nice name though. Maybe there are variants of it? Maybe you could swap the letters around? Dezlen...??
Eden - I have seen this name suggested a fair bit on the forums. TBH, it just reminds me of gardens and green trees - and the chain of gardening stores called 'Total Eden'.
I actually prefer your spelling of Edan though. It looks less 'treeish' and more masculine to me.
Sorry if any of this offends - I tried to be constructive!! Again- I think Rowan is kinda cool.