Is 10k/5k good enough? does breathability matter as much as waterproofing?
Could be fine for cold and dry conditions. Both are important.
If conditions are warmer and or wetter then a higher degree of both will be much more comfortable.
Personally I just go with goretex, it's very waterproof and very breathable. My wife tried a cheaper alternative once and after a week dumped it and went back to goretex.