Quite simply you've made the best choice already, to get a Kemper.
Personally I've not run FRFR yet because its a real step change. I bought the powered version so I could just plug into a regular guitar cab and run like a regaulr guitar amp. Many people will tell me Im not getting the full experience because I've not gone FRFR, but it still sounds fantastic. Someone actually told me last Sat how good my guitar sounded ( despite my playing 
).
So, as mentioned it comes down to cost, powered gives more options ( you lose nothing getting this version) but generally costs more. The non powered can be powered either by an active cab or separate power amp.
The choice is more whether to go FRFR/PA or regular guitar cab.
I think either way you can't go wrong!!!