It may not be the easiest pill to swallow, but have you considered getting a more expensive router?
I bought an ASUS DSL-N66U about two weeks ago and you can customize just about anything on it. I also experience unstable connections quite often, but that's because Telkom has so many dirty copper connections in my area that my SNR spikes too high (between 6 and 9db). The router allows me to adjust the ratio on the router to stabilize the SNR. Doing this sacrifices a bit of speed though, but it definitely makes the connection more stable
I'd rather do this than get grey hairs from being offline every-so-often. We'll get fibre one day and it'll all be over