Here's a much larger resolution of the publicity shot.
Hopefully, it will allow better analysis of the ensemble.
Oh yeah, thanks dude!
Yeah, that's definitely just a shirt with the top button done up as opposed to a cravat. The shoes look to me like shinny black versions of Smith's later shoes but with thicker heels/soles which give the elusion of Eccleston's doc Martin's. I've also noticed a ring on his hand, something that I noticed Hartnel also had. I think those might be Smiths trousers too. They're certainly similar.