If you can find a way of getting to Manchester in the early hours, National Express have departures as follows:
0130 (arrives 0640, connect at Birmingham, with a 50 minute wait)
0340 (arrives 0855, connect at Birmingham, with a 30 minute wait
0355 (arrives 1015, connect at Birmingham, with a 25 minute wait)
http://www.nationalexpress.com
However, your best bet may be to drive to Manchester Piccadilly (or persuade a friend to take you there) in time to catch the 0642 train to Leeds. It arrives at 0739. You've then got a 45 minute wait until the 0824 service to Kings Cross, which arrives at 1047. From there you can either take the Piccadilly Line direct to Heathrow or take a 10 minute Tube ride to Paddington (on either the Circle Line or the Hammersmith & City Line), and get the Heathrow Express from there.
http://www.nationalrail.co.uk/
Chris