Box gutters to "flat" and low pitch roof sections ground floor. Traditional channel gutters to second storey.
We had not one plant in our block. This meant we could steer away from the gutter blocking leaf shedding types. We had a gutter guard at our old 2 storey house. Was ok.
I think they tend to be box gutters on the ground floor and normal/external (maybe some box gutter depending on facade) on first floor. Also ground floor roof pitch is generally flat, but first floor is around 18 degree pitch, once again what you have may depend on facade.
You can ask TA to do external gutters if you're happy with the look.
In our original design we asked for all the box gutters to be replaced with external gutters (to avoid maintenance/flooding risks of box gutters) which TA were able to do. They were able to locate all the gutters/drainpipes along the side of the house on the ground floor so it barely changed the look of the facade. We've since changed our design and facade so not sure yet if it's 100% possible with our new design/facade yet.
As for gutter guards, I've also thought about this but not researched. Seems like a good idea... Something I'm putting off until later once we're not broke from building the house anymore