Sorry to hear your cat has got this, but cats can live a long time with kidney disease, neeeeeeeeeek. We had two who developed it - one at around 10+ years, and she lived another three years (it was something else that got her in the end, not the kidneys) and another who was diagnosed at around 13 and lived for another year and a half.
We had them on Fortekor - one took the pills happily, the other had to have them ground and mashed into her food. We were also given a food supplement (mix into food) called Ipekatine - I think that's another one of those that binds phosphorus so the kidneys don't have to process it or something like that.
Like you, we didn't have very good luck with the special diets. Both of ours refused to eat the biscuits and were very picky about the tins and packets (they would lick the gravy off and leave the rest). So then they started losing weight.... In the end we decided it was more important to keep their weight up and so we alternated, giving them ordinary cat food with the supplements half the time.
When they go off their food, as happens more frequently with kidney disease, very small portions of something tempting (turkey, Philadelphia) hand-fed could often tempt them back on. Not good for the kidneys, I know, but on the other hand, keeping them eating is a priority.
Water is also crucial. We started keeping a water bowl downstairs in the kitchen and upstairs in the bathroom so that there would always be water nearby.
At any rate, I hope that's helpful - and that Binky's with you for a while yet!