Types of Gogatsu Ningyo: Mainstream is Yoroi Kabuto roughly categorized to Kyo Kachu, Kyo Kabuto, Kyo Yoroi and Edo Kachu, Edo Kabuto, Edo Yoroi which are hand made by artisans. And mass product goods.
To save a boy from disease and disaster and hoping to be a person of consequence. It is said that begun to desplay in Edo period for the Tango no Sekku (Boys' Day) To be the top of Bushi.
Difference between Kyo Kabuto (Kyoto) and Edo Kabuto (Edo as today's Tokyo) Briefly, Kyo Kabuto is Traditionally and detailed. Edo Kabuto innovative and decorative.
Sword and bow: Some displays these but meaning is not for battle. Bow means against evil and sword (believed the soul live in). Has been used for rituals.
If you have come interest of it here you can buy direct from Japan through Rakuten Global and amazon.co.jp. here below. "How to Rakuten" on the right side. But maybe don't need to because it is easy to do.
"Kyugetsu" one of the major long established doll manufacture founded 1835.