If the AC breakers and the DC fuse sections of your power distribution panel are functional and not damaged, there's no reason to order the entire package. I'd order just the converter/charger section. It's cheaper and easy to install. HOWEVER: the one you listed:
https://www.amazon.com/Arterra-WF-89...y&sr=8-1-fkmr0 is for a built in assembly and MIGHT NOT fit the space in your existing power distribution panel. It would be "safer" to order the "self contained version" which can be mounted anywhere behind your existing panel without worrying that something might fall against the exposed components and damage or short it out.
This one is essentially the same as what you posted in that link, but is "self contained and designed to fit with both old and newer power distribution panels:
https://www.amazon.com/WFCO-WF-9855-...CBJ3XSR2THBXDX