1. Romney will be more than just marginally better than Obama. I won't get into it more than that. The other parts of the equation however are the Congress and SCOTUS.
2. Keep it the way it is. 4-4-1
3. If Ginsburg were to quit, I would want Romney to find the best Constitutionalist available (BCA).
So you say:
1. Romney will make a better choice than Obama to replace Ginsburg.
2. A good choice would mean to preserve the current status in terms of judicial ideology at 4-4-1.
3. A good choice for Romney to replace Ginsburg would be a constitutionalist.
Taking your words at face value then means you believe Ginsburg is a constitutionalist. That would mean that Bryer, Sotomayor, and Kagan are all constitutionalists as well, since they, together with Ginsburg, comprise one of those "4's" you spoke of earlier, that you wanted to preserve.
Conversely, if Ginsburg is a constitutionalist, that means Roberts, Alito, Thomas, and Scalia are not.
Yet you are a conservative, and you want Romney because he will influence who is picked. And he most certainly is not going to pick someone in line with Ginsburg.