It is interesting that there have been posts about archive tools appearing upon the Planet Debian.
Recently I setup an instance of rebuildd which worked nicely once I'd installed the required dependencies manually.
I also run three instances of reprepro, but there life is not such a happy picture.
I might be using reprepro incorrectly, but despite fighting with it for some time I cannot coerce the software into allowing me to upload the same version of a binary package for amd64 & i386 architectures - something I frequently want to do.
On the face of it importing packages into a small database doesn't seem terribly difficult, but it is a problem I've not spent much time looking at yet.