With that length of guttering you will need a lot more downpipes than you think.
Similarly, with your "pots". A decent downpour will drop a surprising amount of water on the roof which will all end up in the guttering.
We have stainless-steel gutter, pretty slim and unobtrusive but with a surprising capacity.
We got a man in, they have the kit and the knowhow, it's definitely not a solo task!
Sadly, I don't recall how much it actually cost, but it wasn't cheap.