Hiplock Homie or Oxford Chain10 (considerably cheaper) are both nice and long chains, from personal experience d-locks can be tricky if you're trying to secure a Bullitt due to the chunky seat tube.
Alternatively as mentioned above a small d-lock through the wheel/frame is going to make people think twice about pinching it if left unattended for a minute or two
Hiplock Homie or Oxford Chain10 (considerably cheaper) are both nice and long chains, from personal experience d-locks can be tricky if you're trying to secure a Bullitt due to the chunky seat tube.
Alternatively as mentioned above a small d-lock through the wheel/frame is going to make people think twice about pinching it if left unattended for a minute or two