Hey, you should have PM'ed me, I would have been glad to answer any questions. Funny I found this thread just browsing through the newbie chat, didn't search or anything, lol.
First of all, since you have a v1.0 Xbox, I need you to check http://www.xbox-scene.com/versions_1.php
and tell me what video encoder you have.
The softmod I use and recommend (as it is the newest softmod and works great for the VGA mod) is Krayzie's Ndure Installer v1.1. But since you used XboxHDM to install your softmod, you don't have that option. UDE2 is pretty outdated, I didn't even perform my first softmod until UXE was already out. Usually, there's no reason to upgrade your softmod if it works just fine for you, but since you have a VGA mod in mind, it's time to look into it. Fortunately, Kingroach has made an NDURE installer for XboxHDM and I'm actually working on a tutorial for installing NDURE through XboxHDM. I'll try and get it done in the next couple of days (I'll work on it today a little bit).
The best plan of action would be to completely uninstall your old softmod and go back to retail, original, unmodded Xbox. Then, use my NDURE - XboxHDM tutorial (in a couple days) to install NDURE.
Let me know what video encoder you have and if any of those steps will be a problem, I can help you out a little bit more when I know more about the best way to go about this.