Hi Craig,
I fly helis (450 size up to large gassers, and everything in between, electric and IC) as well as jets and all of the heli gyros (to the best of my knowledge) have normal mode and heading hold mode, and you can assign either or both to a three position switch. eg. you might have the gyro off in one position, mild gain on the second position and high gain on the third switch position. Don't be deterred by the fact that the instructions say they were designed specifically for helis, they will still do what you want. The manufacturers just say that as a heli is the most demanding application for a gyro. If it works on a heli, you can be assured it can do the job on your jet.
AVCS is futaba speak for attitude or heading hold mode. Don't use that mode. Use normal mode only. It sounds like you may be after 2 axis stabilisation. If that is the case, look at the Futaba 352. It has twin axis, single channel operation with remote gain adjustment on both channels. If you want stabilisation on 2 axes, and you are running 2 channels on each axis (probably unlikely) then you need to go for either a Futaba 351 or ACT fuzzy pro for each axis you wish to stabilise.
I have only ever used JR servos with futaba gyros in my jets. Best to locate the gyro between your receiver and your powerbox to protect your gyro from the high current draw generated by your servos.
If you just want single channel, single axis stabilisation, try a futaba 520 gyro. Very small, very powerful, very fast, very reasonably priced. AU$173 at
www.perthrc.com. I have one in my flash and it works really well. I fly JR 12X. Let me know if you need a hand with the setup and I can show you my program. I am pretty sure it has stick fadeout or stick priority as you have referred to it. That is a must for our applications. I know the Futaba 351 has it on a dial on the main unit as I have used it. Futaba call it "control gain". If you don't have this control gain on the gyro you can generate it using a multipoint mix on your radio where you mix, for example, aileron input to the gain channel in an inverted "V" shape so that at centre stick you have max gain and at max stick deflection you have no gain. I think that is what you are after and for good reason. Most of the modern gyros have this within the unit's capabilities.
Hope that helps.
Craig.