Would Cheney even run in 2004? He's never been particularly interested in the Presidency, although he did effectivly select himself as veep in 2000 and this does give him (some) more control over American policy than usual.
It is quite possible that he would pick some suitably conservative cantidate, groom him for the Presidency , and then announce that he is not running for a term of his own in 2004, and that he endorses his veep for the top job (perhaps with Cheney as vice-president, although that may be pushing things). If so, any thoughts on who he would pick? remember, this candidate has to get through the 107th Senate, which is technically under Democratic control (election of 2000 made it 50-50, and Jim jeffords caucased with the Democrats from 2001 on; Cheney cannot cast a tie-breaking vote if the split is even).