svnserve behind a frontend server proxy

Question

I'm looking to see if there is an existing solution for setting up a subversion repository that sits behind a redirecting proxy system, and uses svn+ssh.

Example:

+BeS1-+  +BeS2-+ 
|repo1|  |repo2|
+-----+  +-----+ 
     \       /
   +-FeSys------+
   | redirector |-+
   +------------+ |    <== clients point to the FeSys and the redirector
     +------------+        proxies to the correct backend.

   client: svn+ssh://FeSys/repo2/trunk/blah blah gets "served" by BeS2
   client: svn+ssh://FeSys/repo1/trunk/blah blah gets "served" by BeS1

The client never talks to the BeS1 and BeS2 systems directly. FeSys is a collection of systems that have a common virtual hostname (redundancy and load balancing)

Currently doing this using a custom rewritemap program and apache proxies.

I'm now looking at trying to do the same with svnserve (basically looking for ideas for the "redirector" part).