Tony Stark created the very first Arc Reactor to keep him alive - and power his first suit of armor in - the original Iron Man film. Based on the first Marvel Studio production - Iron Man, Hot Toys has a new piece from their Life-Size Masterpiece Series with Tony Stark’s Arc Reactor which was given by Tony’s personal assistant Pepper as a desktop ornament. The Arc Reactor stands approximately 6 inches in height. Recreated with diecast and copper wire material, it features two LED lighting modes, which include a light-on effect and a breathing light effect.
The piece is scheduled to be released around Q3 of 2020. While it's not currently available to pre-order at Sideshow Collectibles, I'm guessing they will have it up following San Diego Comic-Con.