The start, very easy first target, then lots of room to expand or a good next target to attack. You don't need perfect settings for a space win, this would be more than good enough. Didn't want to go all the peaceniks because that's not necessarily easier. For fastest possible space you want tech pace as fast as possible, but for first space it's easier with a bit slower AI tech pace. Having a mix of different minded easy to bribe AI is one good way to achieve this and also the easiest way to make sure you're on good terms with your neighbors. Apart from Darius all of them can be bribed at pleased or lower. Any target will also become a soft target if you can send their army elsewhere before declaring.