Almost certainly you can keep your current backup camera. The connectors for accessories such as cameras tend to be universal so any camera system can plug and play with any in dash unit. If yours is a rare exception, there is likely an adapter plug for a few bucks.
You can order the unit and if it doesn't work, return it- but I'd be very surprised if there was a problem. Disclaimer; I am not an installer or expert, but have learned by experience that almost all components are universal or easily adapted. It's the only way so many different brands and models can exist in the marketplace. Hope this helps.