Regarding uptime, you could cache the output of Yahoo Pipes on your server in case the feed goes AWOL for a short time (though as PascalMartin said, their uptime is very likely better than yours).
It's unlikely that Yahoo would suddenly close Yahoo Pipes but if they did I'm sure clones would start springing up. Worst case scenario it wouldn't be too difficult to write a custom program/script to fetch a bunch of feeds and filter them on your criteria.
