peer marking process

Just when I thought I had done enough on paperless marking for a bit, up comes peer marking! arg!
We want groups of students to be able to give each member of their group a mark based on their evaluation of the relative contribution each made to the project: they will effectively be asked to assess each other on 'teamworking'. This will make up 20% of their final mark in a summative group project.
We did something similar using paper a couple of years ago and I collated the marks manually via excel and then did a mail-merge to send students their individualised score.
I have been doing a first trawl of likely options but blackboard appears to be something of a let down. Moodle has a 'Workshop module' http://docs.moodle.org/en/Workshop_module which may offer just the kind of thing we need - apart from getting someone to code it up for us bespoke. Here are some initial thoughts:
Easy group creation (upload a simple file with names, email, groupID, CohortID, ModuleCode)
The main interface is a kind of questionnaire:
List of group-member names along side (<=10)
List of criteria along top (<=5)
Grid with totals at the ends, confirm scores page.
Tutor users can add in the rest of the final mark (i.e. 80% using their own editable marking rubrick page - as above but including a comments box) edit scores and query to discover pool scores.
Option to email pooled score to each student once a deadline passes.

hmmmm...