sooooooo......
the decision was not all that difficult after all! I managed to compare not only the 6000 with the fuji x-e2, but a colleague of mine was here this afternoon and brought his A7. We fired off a few shots to make a comparison of the low light performance. All shot in RAW at ISO6400 and processed in Darktable in exactly the same way.
Sony A6000
i was surprised at how noisy the image was, what I also noticed was the auto WB had problems. it is not so noticeable on the forum post but in darktable was clearly visible.
Fuji X-E2
even though there is noise it is well within limits and noticeably better than the A6000. The A6000 AF was maybe a tad faster in low light.
And finally the A7. I was surprised at how much noise was present from a FF sensor, my colleague also was surprised when we compared the images from the fuji to the A7 and saw no great difference!
I have decided for the Fuji as the low light performance is an important factor for me and the price is well within my limits. the operation is going to take some getting used to though! Thank you all for your help and suggestions. I look forward to posting in the fuji thread which Eduard started a while back!
Kind regards
Martin