They are a part of this mod, and to my knowledge, aren't for reuse.(atleast, not without proper permission and credit).
My memory and knowledge is less-than reliable, though, so I'm certain Phoenix or some other high-ranked individual will swoop in and give you the low-down.
Don't worry about it,I never re-release other peoples work
The Youtube video was probably our promotional video for our 1.0 release. Generations Arena is a Q3A mod that combines the weapons and playing styles of Doom, Quake, Quake 2, and Wolfenstein-3D (with a lot of liberties to Wolf) into the Q3A universe. The .99f version for Q3A v. 1.32 can be downloaded here.
The weapon models, etc, that we have created are not for distribution outside the mod. That includes porting them to another format, or modifying them in any way. You can do what you want with them on your own computer for private use, just so long as you do not distribute them in whole or in part. If you're wanting to make your own models you cannot just use ours and tweak them; that's a no-no in the modeling world and also runs afoul of copyrights. However, you can take a look at ours in a modeling program to see how they're put together and then design and create your own using what you learn. Most modelers, myself included, learned how models work by examining other people's stuff, figuring out what is what, and then making our own material.
If you're seriously interested in learning how to make your own models definitely feel free to ask questions here. We like to help fledgling modders when possible to get off in the right direction. As for programs, Max is powerful but has a steep learning curve. QME I'm not too familiar with, and I know nothing about Blender. I can say that if you learn Max it's an extremely powerful program once you understand how to use it. As long as you can export to the format you need to use in Skulltag it will do anything you could possibly need it to. Tab and myself are also familiar with the program a bit, though Tab's more the expert with Max when it comes to actually using the program to create things. My expertise is more on the import/export side and integration with the program code, texture pathing, shaderizing, etc. Most of my mesh creation has actually been done in the old Q2 Modeler program, but ask either one of us a question and we'll do our best to answer. 
I'll go fiddle around with 3dsmax so stay around because I probobly have a few questions later.
