I have not really looked into the total eye relief of any of them in particular yet, I don't have the cash to buy one now is why, but I think the Leupold will work great for my situation though. I'm not sure what power I'll get it in but they also seem to be a bit more generous on eye relief than the others I looked at, in addition to being easier to look through.
This is one of the main reasons I went with a 3.5-10x40 VXIII for my 416wby, the eye relief. Turns out though, I cannot get back far enough with a proper cheak weld to even make use of it all, even with it forward all the way and an extra 1" length of pull. I thought I'd need all I could get with the recoil and all, but tuns out it works just perfect.
I have never considered an extended base, but I did see one made by USO lately for using an NVD unit on the ocular of the scope, this might work perfect though. I want to keep the scope where it is though, so I'll just switch it out with a rifle scope in the future. I have a shoulder holster type affair for it, and it just wouldn't work if I moved it forward any more.
I position the scope up real close right now, and would like it almost as close as my rifle scopes so how the scopes sight picture looks and reacts when my eye is off center to the scopes axis is what largely determined my choice. This happens quite a bit to me as I aquire the target in a pistol not having a butstock. The leopold seems to allow ones eye to be more off center and still retain the sight picture better, this is a big part.
Good luck on gettin it all fixed up, whichever way you go.