Please don’t. ;)
A better thing to do is to join the design discussions and development of the nextgen VyOS. vyatta-cfg must go away, or we all are doomed (see http://vyos.net/wiki/Old_backend).
If you still want to proceed, I’m not sure what you mean by “doesn’t support dpkg”. If you are porting it to another platform and another distro at the same time, you can hit many weird problems because there are lots of filesystem layout and packaging system assumptions. And without precise information about the way it doesn’t work it’s very hard to tell anyting.