I really like the name Ryan, I always have. I think it's very handsome. I don't even care that it's popular and actually it must be declining in popularity by now so your son might not be Ryan F too often.
I don't know if this would bother you, but personally my only concern with Ryan on a boy, is its growing popularity on girls. I feel like Ryan may become the next Taylor or Ashley or something, but if that's okay with you than I say go for it.
Ryan Robert Alasdair is very nice...I prefer it to Robbie just because it sounds a little more "professional" (weird way to describe a name but it's the first name that came to mind).