A580 upgrade ?

Would any camera from sony's current lineup give me significantly better image quality?

My current kit is :-

Sony A450 and A580 bodies + 70-400G and 100mm macro lenses.

Tamron 18-250 and 200-500 lenses.

I mainly shoot wildlife, sometimes in poor light, and crop quite a lot - processing from RAW in LR.

I have no interest in video or in camera processing and cannot afford prime lenses.

Noise is discussed quite a lot on this forum so I should perhaps say that I often use ISO 1600 and occasionally ISO 3200 without problems and can use LR for anything that needs adjustment.

Thanks for reading.

deek11