You can get the same performance boost without the footgun of C if you use e.g. Go, I've done so for a while now and I'm quite enamoured by it. Possible downside is that it ships with a runtime, so binaries are at least 10MB (before optimizing for size).

That said, you mention PHP, I wonder how PHP running in HHVM compares to a more bare metal solution (or regular interpreted PHP).