It was played live a few times on the AFDTE tour (I have a bootie of the Dublin gig where they played it) and they also played it lately on the AND tour I think.
For me it is J'ai Fait Une Promesse. Although I normally do not prefer the early catalog of Anathema, that track is simply breathtaking to me with its honest and compelling longing.
For this moment -A Natural Disaster- but it could change tomorrow
About other female vocals I have version of Sleepless singing by Vinny with some woman maybe Michelle Richfield I'm not sure but this version is great better than this one with Darren - my opinion
Sleepless 96 also appeared on the recently issued digipack of The Silent Enigma, the female vocals are a great contribution to the song, dunno who's voice it is