Fit the parts you already have, use the gun and work out what it actually isn't doing well enough. Don't chase improvements that aren't there just because you can swap a part for something more expensive, it doesn't always work like that.
Personally I wouldn't bother trying to DMR an Orion gearbox.
Shimming and motor height have three parts of fuck all to do with trigger response unless it's completely wrong to start with.
Stick with the zci hop unit, it's fine.
AOE will also be absolutely fine, leave it alone. If you have good compression then that's all you can ask from your cylinder/ piston etc. Leave it alone unless it breaks.
Yes, the Perun will be an improvement on the x-asr as that is the most basic of basic mosfets. I would go with a Gate Aster and USB link so you can make changes from your phone but I like gadgets.