Distinctive modern art and memorabilia owned by the late American actor Robin Williams is set to go up for auction in New York.

The beloved actor and comedian, who died in 2014, was known for a long career in TV and comedy and also starred in films such as in Good Will Hunting, Mrs Doubtfire, Hook, Aladdin and Good Morning, Vietnam.

With his ex-wife, Marsha, he amassed a diverse collection of art and artifacts, including unusual furniture and installations. The more than 300 items will go for sale on 4 October at Sotheby’s auction house.

The collection includes street art by the British artist Banksy and by Shepard Fairey, famous for the poster portrait of Barack Obama that became the enduring image of his successful 2008 presidential election campaign. On the block, also, will be autographed scripts, props, more than 40 watches and several bicycles Williams owned.

A portion of the proceeds will go to charities the couple supported, including the Wounded Warrior Project, the Christopher & Dana Reeve Foundation, the Challenged Athletes Foundation and the Juilliard school, a prestigious performing arts conservatory in New York.

Robin Williams auction items on display in Los Angeles on 12 September. Photograph: Eugene Garcia/EPA

“Robin’s favorites were as mutable as he was,” Marsha Williams said in an interview featured in the Sotheby’s catalogue. “It might be a different answer every day.”

Robin and Marsha Williams were married for more than 20 years and divorced in 2010. The actor killed himself in 2014.

Among the items being offered for sale:

Williams’s best actor Golden Globe award won in 1988 for his performance in the film Good Morning, Vietnam.

A robe from the fictional school Hogwarts, with the Gryffindor house crest, worn by actor Daniel Radcliffe during the filming of Harry Potter and the Sorcerer’s Stone.

A bronze horse sculpture by artist Deborah Butterfield, specially commissioned for the Williams’s ranch in Napa, California, that the auction house estimates is worth between $220,000 and $280,000.

Five works by Banksy, including Christ With Shopping Bags – depicting, as the title suggests, Jesus on the cross with gift-laden shopping bags hanging from both hands, and Happy Choppers, showing military helicopters adorned with pink bows.

A Greetings from Iraq stencil by Shepard Fairey depicting a bitter parody of war.

A pinball machine whose theme is the movie Hook, a gift from Steven Spielberg, the film’s director. A dagger and sword used as props in Hook are also being auctioned.

In the UK, the Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Hotline is 1-800-273-8255. In Australia, the crisis support service Lifeline is on 13 11 14. Hotlines in other countries can be found here.