By presumption that say "something is better for nothing" will post my solution og this case. It's ugly but useful for me 
In file /usr/share/vzyum/lib/yum/__init__.py in YumBase -> getReposFromConfig somewhere after line 105 ~ 106 I added next code:
vpsrepospath = ('/etc/yum.repos.vps/%s' % self.conf.vps)
if os.path.isdir(vpsrepospath):
self.conf.reposdir.append(vpsrepospath)
Then in /etc/yum.repos.vps/1003/ I can create .repo file that contain required additional repos and ... I'm happy 
vzyum 1001/1002 ... read repo only from /vz/template/centos/4/i386/config/yum.conf but vzyum 1003 adds and repos from /etc/yum.repos.vps/1003/*.repo filed. Cashe is still the same for one OS tempalte.
I'm not skilled python developer ... even I'm not developer at all. May be have some other good solutions for this case. First I was try to make it like a vzyum plugin (yum plugin ideed) but fail ... maybe because old API (version 2.1), maybe because I don't have enough developer skills
That's all folks 