I'm guessing that vBulletin isn't going to look like the old layout no matter how you tweak it. It has it's good points too, just have to get used to it. I spent years on v so it's not a problem for me. Give it a chance.
We're looking into other designs, but this is one whole version newer then the old forum and that design will not work with the new forum and all of the new features..! Don't worry we're workin on it