Thanks to everyone who has voted so far, it's helpful to hear other people's opinions, although we're still no nearer to making a decision.
It seems Joseph and Theo(dore) are the current favourites (by far) with MN, then Ivo and Otis. Not many people seem to like Heath! We've taken Heath off our shortlist now as it's the name we like the least.
Joseph was going to be DS's middle name but as we can't find a first name we love we're now considering using Joseph as a first name instead. I prefer Joseph to Joe but inevitably it would be shortened to Joe if we choose it as a first name. I'm also concerned that as it's a top 20 name there will be other Joseph's in DS's class or school year.
I really like Ivo at the moment but am concerned I'll go off it. It seems to be one of those names people either love or hate. I haven't read any Georgette Heyer btw so don't know how the character Ivo is portrayed in the novel.
I used to love Theo and it was a serious contender but I'm put off by it's sudden rise in popularity.
I'd prefer to have a name that's slightly unusual and not a current trend.I'm going to spend the weekend looking through name books (again) to see if I can find any alternatives.
Thanks again for the comments,
Digital x