Hi Jez I've been impressed ...
Published by Stuart Stapely, NRW Manager at Detection Services
Hi Jez
I've been impressed by LeakIntel from Visenti in Singapore.
It may offer more than what you've asked for, in that they use high speed loggers (250Hz) to locate transients and determine condition assessment as well as detect and locate new leaks.
http://www.visenti.com/?page_id=206
Cheers
Stuart