It's obvious that Itachi will take this one. Hiruzen has no conter against the Sharingan, neither against Tsukuyomi and general Genjutsus, nor Amaterasu and Susanoo. A higher stamina, more physical strength and speed won't be a help for prime Hiruzen. It seems you forget that Itachis illness had made him weaker too. Hiruzen hasn't shown the potential to defeat the (Mangekyou) Sharingan, so let's be honest, neither Hiruzen in his old age nor in his prime will defeat Itachi.