I'm very unsure on what kinda lens i should be getting for fashion photography and i'm hoping to just invest in one lens for now, period.

I really like these photographer's works:
http://www.milesaldridge.com/

and particularly this set by Mario Sorrenti:
http://i36.tinypic.com/2j5dz46.png

http://i33.tinypic.com/15wdv01.png

Can anyone tell me what kind of lens these two are?