Thanks for the replies everyone, some great tips in there!
I'm going to do this properly, and plan out quite a few things before I begin, i'm going to try and recreate Bastion's settings in quite a few ways, but im going to take a lot of liberties to translate it all into a dwarfy context.
The wilds that you explore in bastion are a terribly chaotic jungle, so my embark location will be a suitably savage jungle (which will be hard, but when did difficulty dissuade a dwarf?) the city itself will float above, and underground I will build the gasfella mines!
I'm going to have a bit of fun (of both the dwarfy and non-dwarfy kind) segragating my dwarves into castes, following themes of the game, with the masons(builders), breakers(archer/hunters), gasfellas(miners), Brushers (spearmen/hunters) and all the rest.
The city itself will be the main focus, I will try to burrow diferent groups to their respective parts of the city, but the Bastion itself will be in a central location and will be off-limits for the majority of the time, stockpiled with plenty of food and will be a near-impenitrable last resort, in an emergency every dwarf will be burrowed to it so they all flock inside, it can be sealed off and in the case of a dire emergency we can pull the calamity lever, which will collapse the tunnels undergound and all of the city save for the bastion itself, then we rebuild.
I will dangerroom a single dwarf (I tend not to use the things, but I feel this calls for it), give him all the best gear I produce and name him "The Kid", he will be the great protector of the Bastion. He shall be a legendary Hammerdwarf, its a shame that dwarf AI doesnt allow me to load one of each weapon onto him, and for him to choose the best weapon for each situation...