Pour Homme is the safer, more conservative choice. I would not say 3rd Man smells like Egoiste exactly. It is very distinctive, but should probably be sampled first. It probably is a bit "cloying" to some people.
Read in the directory about 3rd Man and see what you think. I have a small bottle and it is very nice. But maybe toooo nice. It is very "pretty" as Luca Turin's Guide says. I wouldn't call it feminine, but I know a lot of women like it and wear it. It is a very well designed and crafted scent.
I don't find many occasions to wear it. Too many scents in my wardrobe that I like a lot better.