I'm sitting in Hong Kong right now trying to sort one out for a friend here. I've gone through britrail and cap and have the one month options only.
The speed of your response was impressive......
I've just checked, and it does appear that only the 1 month options are being offered. Checked by browsing from a few different countries, all show only the 1 month options. See attachments:
BritRail website info pages also only list consecutive and 1 month option.
http://www.britrail.net/passes/britrail-pass
Same goes for acprail.com. Only offering 1 month passes.