From what I see on your mock up it should take at least 2 hours. If you want to theme the scroll....well good luck, it's very discouraging. A complete theme usually takes 3 days to complete; it all depends on your motivation, organisational skills, working habits and how complicated the theme is.

By the way, you can't make the titlebar or menubar bigger or smaller than 22 pixels. Use Themepark to create a theme.