Custom packages, subversion - best practices ?

[Przemyslaw Wegrzyn <czajnik@czajsoft.pl>]

Hi !

My question is a little bit off-topic, as it is not about Debian development, 
but rather Debian-based development, but anyway I think someone could answer 
on this list. On my servers I need to install lots of packages that need some 
customizations. Usually I download deb package sources, modify the, build 
package and dpkg -i  it. However I'd like to have more control about it, so I 
decided to put my customized packages under version control - subversion in 
my case, as I don't use CVS.

Let's say I want to change something in apache-1.3.31-4. 
After apt-get source and importing sources I can do svn cp (as subversion has 
no tags or branches, instead using "virtual copy" operation) to a directory, 
let's say apache-1.3.31-custom and make my modifications there. 

Now the questions are:

1. What is preferred subversion repository layout for such needs ? Could 
anyone give some advice ? 

2. How to handle new debian package releases ? (say, apache-1.3.31-5 is 
released, and I want to reapply my modifications to it).
Of course I will make a diff of my modification, and try to patch a new debian 
package, manually fixing failed hunks. But again details depend on how I 
layout my repository - I'd like to make it as automated as possible. Any 
advice welcome.

BTW, how can I quickly generate diff between 2 given debian package releases, 
say apache-1.3.31-4 and apache-1.3.31-5 (of course other way than downloading 
manually both versions and running diff) ?

Best Regards,
Przemyslaw