Handlebars for an upright seated position
You can likely find bars the will fit, but keep in mind that you still want the bike to function which means moving over your shifters and brake levers. While you could probably do this as a DIY project, I'd really recommend going to a bike shop and at least getting some advice first.

The can help you select a bar that is the right diameter to fit with your current stem and talk you through issues like re-cabling (longer bars probably mean longer cables) and where/how to mount shifters and brake levers. You might end up wanting to change brake levers to a different type depending on bars.

Don't forget the you still need to be able to get on and handle the bike. You will be doing some strange things with the center of rotation for the bars. At low speed (...i.e. the speed cruiser bikes that normally have these bars), this is probably not an issue. But you get up to high speed on a decent and you might find yourself in trouble. Start slow and see how it handles.

Happy riding.