I'll settle for a brilliant strict-constructionist conservative, but whom do you like, and why?
I'd also consider a really good senior military judge advocate who has worked on implementing the proposed terrorist tribunals, because the Supremes have shown they are clueless about the real world effects of their decisions on the normal criminal justice system. Apparently the only way they can figure such things out is when one of their own has worked in such a field - Rehnquist valued Justice Thurgood Marshall's insight into litigation based on Marshall's vast litigation experience. There is no way the Supremes can give us anything reasonable concerning the novel concept of military tribunal trials of terrorists unless one of the justices has actual experience in that field. At the moment that means a JAG.
Beyond that I'd want justices with something like Ashcroft's background - former state attorney generals who had also served as a U.S. Senator or state governor. The Supremes as a group are notably lacking in real world experience and judgment.
But for Chief Justice we need someone with proven leadership ability, and there Guliani has no peers among those with the requisite legal background. He's a better administrator than a lawyer (and his record shows he is a very, very, capable attorney), but his leadership ability is amazing. He can do the country the most good as Chief Justice.