Hi,
If non-isolated is an option, why not use a current shunt monitor with programmable gain? They are easy (like everything in electronics, "easy" is relative but these are truly simple) to implement, they use Kelvin sensing, you can select one for the output range to fit the ADC used and you can include some margin for surges. They must be available everywhere, they are such a common part.
The BigBoss person here posted a great little Hall effect (so isolated) current shunt monitor IC a few months ago as a suggestion to a current-measuring thread, maybe Allegro make it..., I just looked and can't find the datasheet online because I do not know the part number by memory - sorry. Maybe someone else here on the forum will remember the device I mean.