You will generally get better results if you create your own post rather than attach a question to the end of a post that is already marked as answered. I only opened this up to see what had been accepted as the answer to the original question, otherwise I wouldn't have even seen this.
The Gateway can access any http shares on the core server, even if they are internal only. Any share that's off the core would need to be be public. UNC shares should be avoided.
The easiest thing to do is create a packages directory under ldlogon on the core, because it's already http shared with appropriate permissions for software distribution. You should be able to set up a policy based on that share (as an http share, not unc) and deploy it just like you would within the normal LANDesk environment.
I branched this to a new thread for you.
Through the gateway you must have the package in either or both of two locations:
1. On the Core as a web share (Not UNC).
2. On a public web share.
You can push to a client computer if your core is behind a MG, but that client computer must be open to the core--either not behind a firewall, or with the appropriate ports open. The repository can either be a webshare on the core (which doesn't have to be open to anything aside from port 443 on the MG--ours is completely behind the firewall), or on an external http or smb share that the client computer can access. It's easier to do it on the core, I'm finding out.
Policy supported push seems to work quite nicely--if the machines are open to the core (ie, the core can directly contact the agent), it gets the package immediately. If not, it becomes a policy, and the machines check in and pull it down at the specified interval (set up in the agent configuration before deploying the agents).