I have built beowulf clusters before.
There's no point in building a beowulf for folding- folding is not properly threaded for smp let alone for beowulf.
I would recommend putting linux on them, though.
Make one a NAT server- a gateway to the rest.
Then set the others up to run folding from the crontab and just let them run.
That will install the folding@home client on x86 linux, utililizing your crontab.
To manually stop it- just touch /tmp/stopfold
To start it again- rm /tmp/stopfold
Once its running- just leave it alone.
The only thing you *might* want to do if you are super tight on hd space is to modify /etc/syslog.conf to no longer log cron job calls.