[Hampshire] Access rights

Hi,

I have an svn server, that a number of people are using in the office.
How do I get new files created in the svn repository created with
owner svnuser, instead of the actual user that is logged in. I also
want files created in repository1 created with
user-id:svnuser1 and repository2 using user-id:svnuser2.

I am using ssh+svn.

Currently, I have a bit of a cludge, whereby I have a sticky directory
group bit, so all files have the svngroup set on them, and then set
the user's umask to make them group rw.

Any ideas?

James