The problem with the Orange Patriot is finding somewhere to fit the battery.
One of our eZee kits would give the performance you are looking for off road and it looks like the only solution for the battery would be one of our seat post mounted MTB racks, it really depends how much abuse it would get as to whether the rack would take it?
eZee MTB rack which also has a bracket for mounting the controller
If you just want it for off road jumping and stuff, it needs to be a direct drive motor because the impacts during jumping can damage the internal gears of a gearedmotor. Direct drive motors are big and heavy, which will spoil the rear suspension. A crank-drive kit would be much better. I think your only option is a battery in a back-pack like the Ego kit. See it in the video here: http://www.ego-kits.com/
Most of the kits hold the motor on two plates that are fixed to and parallel to the bottom bracket, so check that they don't interfere with your swinging arm pivot. Here's some kits to look at: http://www.electricbike.com/mid-drive-kits/
Are backpack batteries considered safe ?
The Orange doesn't lend itself to a bike mounted battery, but I worry about the safety side of carrying it on your back.
I have a motorcycle back protector that I could wear under a camelback, but even so, falling on it seems risky, not to mention the obvious hazards.
It depends how good you are at wiring/soldering. If you make sure that the wires are properly tied down, it should be OK. Put a fuse near the battery in case of an external short after a crash. A coiled wire to your back-pack would be best if you can find some thick enough.