If you want to go to 2.4 you can buy a module and replace the module in your unit. You will need new receivers. I went thet way years ago with the XPS equipment. I would not recommend XPS now though, they seem to be getting out of the hobby business.
The Chinese manufacturer FR-SKY makes first class equipment and it is cheap. Dont turn up your nose because its cheap. It works.
Futaba equipment has their equipment made in China. They just charge you $$$ to put their name on it
Try Aloft or Value hobbies.