I'm an Airtronics expert and for a first class ticket to Maui I will fix all your issues.... No? OK, good choice, not really an expert anyway...
That said, I have used 94102 stuff and the ball bearing version 94322 with the -3 stuff along with the 94162 giant scale servo. The latter gives 144 in/oz at 6v with .18 sec / 60 degrees and meets my needs for 1/4 scale or 1/5 scale warbirds. But I have enjoyed moving to digitals and have seen benefits of the -3 speed with digitals though I fly mostly giant scale warbirds not 3D or helis which really benefit from the -3 advantages. I would recommend that you give some thought to moving to digitals and get the benefit of the -3's speed. Airtronics has a wide range to choose from, I like the 94722 and 94851s. I have seen issues with other brands but will not comment on which, don't want to be seen as bad mouthing other brands which for the most part are excellent. I will say that you will have better luck with name brands vs lower cost knock-offs. I would test them first as much as possible. Do you have a junky beater like a stick or Gremlin that you could test the equipment in first?
I can not comment on the RCXL products as I have not used them. Same with Eagle tree, hopefully some else can chime in there.
I can tell you that the Smart Fly opto Kill Switch works fine with my -3 stuff and will work with twin receiver setups which I tend to use on large gas planes.