Clearly it won't be GW. He can't win as he's already served two. RR has already served two also, so he would be ineligible even if he was still alive.
The conservative wing of the Republican Party is somewhat low regarding the talent bank right now. Unless someone comes up in the next year it is likely going to be McCain or Rudy.
Neither McCain nor Rudy are even close to being conservatives.
It is impossible that there is not a capable conservative out there. The whole point of conservatism is that conservatives are independent and capable.
The conservative voices will break through, and then we'll support them.
Oh, I'm sure there are plenty of good candidates in the bank. But if any one of them shows any chance of becoming the nominee, he or she will immediately be branded a right-wing radical, just like Barry Goldwater was. There aren't that many Ronald Reagans than can stand up to a couple of years of that Shiite from the MSM, the 'Rats, and the "moderate" Republicans.