It's interesting. Here (in the US) names like Octavia, Dante, etc, are seen as "chav" (or the US equivalent) probably because they are mostly used in the African American community. 
Tarquin would be very chavvy because it isn't used at all and would be seen as "made up."
Americans who were related to "influential" families used to point out the connection by using those surnames as first or middle name, but now Kennedy, Carter, and Madison are down-market because they've trickled down. If you are actually related it's different. For instance my grandmother's maiden name was Watson, and if I used that as a middle name for a son it would be seen as "classy".
Also, interestingly enough (I just read an article on this), it's not the conservative, Republican Americans who are choosing the solid, older, Biblical-ish names for their children. Sarah Palin is proof of that, eh? She's got a kid named Track for heaven's sake! Meanwhile the liberal set is having kiddos named Frances, Hannah, John, etc.