Switch from Sony, or only the A Mount?

Hi, have a dilemma. I have used my trusty Sony A100 from 2009 to 2017. I don't have any kit lenses, but all are vintage Minolta lenses:

• Minolta - AF 50 F1.7
• Minolta AF 35-80mm F4-5.6 II
• Minolta AF 75-300mm F4.5-5.6 II

I've done a lot of travel, and bird photography with these lenses.

But now, I've after 5 years of rigorous jobs and responsibilities, I got some time for me. And I want to relive my photography hobby. But being an iPhone 11 (company provided) user now, the A100's IQ seems too limited to me, especially in low light the max usable ISO is 800 even with the 1.7 50mm. So for last 1 year, I've ended up using only my phone on my official and personal trips.

I've been somewhat detached from the progress in photography made in the last couple of years and don't know any better than a common person. So, I want guidance from others in choosing a new budget APS-C setup under 1000$ (Equivalent of INR price as I am from India), while keeping in mind the following points:

• I want to keep the camera for a looong time, as I've done with the A100. So the tech that is phasing out doesn't seem good. This is the reason I am ready to sell/dump my precious Minolta collection because I find no future support for A-Mount whatsoever. Even the adaptor costs 19k INR(250$) in India.
• Linked to the above point is that should I go with mirrorless and be future-ready? DSLR ergonomics are good, but I can still adjust with the mirrorless form factor.
• Coming from a low-income group, I want to go with a route that has good lens support. I am also thinking there is a good option to get a body + 18-135/105/140 mm kit, and then buy a used 100-400, 150-500/600 in the used market (India or Canada), like the ones from Sigma or Tamron.
• The goal is again travel photography with my wife, and occasional bird photography, widlife safari's
• Fixed lens superzooms aren't my cup of tea, unfortunately. I've had Fz200 for a brief time in 2016-17, as I couldn't live with noisy images from the tiny sensor.
• Although I've iphone for 4k videos. But having that option in a big sensor device would also be good. Not necessary, but good to have.

Keeping in mind these points, I've thought of the following options but am not sure:

• Nikon D5600 with 18-140mm
• Sony A6100 with 16-50mm (Not sure if it has a cheap telephoto option even with an adaptor)
• Nikon Z50 or Zfc (sometimes it goes on sale selling at only 3-4000 INR more than Z50). Also not sure if it has any cheap telephoto option.
• Fujifilm X-A7 also seems a worthy option. But I don't anything about the fuji's lens ecosystem and their availability in India.

I hope these articulated points are enough to help finalize my search.