I believe the correct answer is a combination of both x/border and form49's answers.
x/border you are right in saying that the transition Level would be FL65 (when QNH=1000mb). The T/L doesn't provide separation, it is the point at which vertical distance is measured in FL's rather than Altitude.
However, the first available Flight level is FL80. Unless of course, in the military, you are authorised to provide 610' separation.
Just my 50p worth
GW