1998 convertible HVAC

I have a 1998 convertible ... and need to replace the HVAC unit.
I currently have the very basic one with two large ***** (heat level and fan speed) and both of those ***** just aren't working right anymore... they just spin beyond their settings.
Also, the actual finish on the face of the unit is peeling away and now you can see the light glow right through the face.
First ... are these pretty simple to swap out ?
Second ... will the other model of HVAC unit with the small digital display and button controls work in this swap ?
Thanks to anyone who can help out here !!!
Bri
As to the first question: I've seen a couple of posts and YouTube videos over time indicating the ***** themselves can become non-functional if the plastic splits common to the shaft hole. The OEM ***** used to be available, but have been discontinued. That said, I'd bet that Dorman or another small parts supplier has a substitute that might fit and work, if not look quite original.






