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You'll need a printing device that is capable of printing oversized A3 - commonly known as RA3 and be able to take paper stock up to 400gsm. That will allow you to print up to A3 size for posters.
Anything larger than A2 posters you'll need to buy a plotter.
You'll also need to purchase a guillotine - and a lightbox - xacto knives.
You may also need to purchase a collating machine, for flyers of 2 or 3 types that need to be bundled together at some stage.