Just as an update, I really like the Alpine ixl-701. I ordered the HU and all parts from crutchfield and had them build the harness connection between the truck and HU. It also included the Maestro. I'm not an expert at all on all this parts and what does what. But even so, with the help of their support, I was able to replace the HU and everything works great. I especially like the handsfree NAV. Since I use the iPhone, it hooks right up to the Apple Car Play and all is good. The total for all this was less than $900, which I thought was very reasonable.
It may well be that the unit Carnau mentions is better and cheaper. I just decided to go with the Alpine.