Sidious would still kick Mace's @$$. Sidious id the perfect epitamy of the Dark Side, just like Yoda is for the Light Side. If you can tell me how Mace would win, i would eat my words, literally.
And look at you Windu6. Mace is in you avy/sig. It's no wonder you're rooting for Mace.
And another thing, why do most people think Mace is the most powerful Jedi, what about Yoda? I'm pretty certain Yoda would pwn Mace.