I see Kuryakyn is now making an extended brake pedal for the Rushmore bikes, @ $99.99 it's quite a bit cheaper then the Softbrake one.
Extended Brake Pedals | Shift & Brake Levers | Pegs & Foot Controls | Küryakyn
Extended Brake Pedals | Shift & Brake Levers | Pegs & Foot Controls | Küryakyn