Aftermarket head unit

I don't know that I've seen one for the Escape (assuming you mean 2013-2015 since the backup camera was standard after that).
Your best bet might be to look on the Focus forums.

AliExpress is sure to have something. How good they are might be another thing.

It makes a big difference whether you have sync 1 or sync 2/3. Sync 1 systems are pretty straight forward with kit's that are pretty easy to find and install. If you have sync 2+, there are a lot more systems integrated into the headunit so your looking at spending $1000 + to get all the components you need to make a switch.