The FX3 is a very good manual camera. The MEchanical Contax S2 shares the same chassis as the 139Q and yasthica FX-3, but with spot metering, with titanium covers, and 1/4000 top exposure. The rare Contax S2b is an S2 with integral metering.
The Aria is a very good camera, light enough, with very good exposure metering (to me it's the best one I've used). But.... it's a motored film transport camera. Viewfinder is so bright, and the information is so well displayed...Perfect light camera for travelling, but have a backup in case of no battery situation. Mine went to Argentina twice in late autumn, to the glaciers with no problems, but it was 15 years ago. Has not seen serious action since 2008, but every month does around 50 dry shots to keep fit
The 139Q, I like it so much, never had owned one but I've bought one recently, but came out defective, so returned it and waiting for the replacement.
The only problem with contax cameras is parts and service, as support has been finished since 2015, but in the US still nippon photo clinic services them.
I would bite the bullet and go for one of them. Love the feel of the 139, feels sol solid and good on the hands,the aperture priority is more than enough, and you have also the choice manual mode, but the camera itself is electronic.
For mechanical bodies, only choice is Contax S2 or Yashica FX.3. I would go for the yashica. Still own after 25 years the contax S2, it's really nice and wonderful, but could have bought a Yashica instead and the 1,4 planar instead of the S2 and 1.7 planar.
After all, I have never shot at 1/2000 or 1/4000, so the FX3 would have fulfilled my needs perfectly
Best regards