Spongly, yup that is the main source for this mod.
I asked Ursca if he had any spare time to make some new helmet models but he is very busy at the moment. I am willing to wait since it would be great if he could do them in his usual quality style, for consistency. There is a single-slit great helm that was also common at the time, and of course the famous angled kettle hat.
Knights actually do use kettle hats, Sidus. The probability for them to wear them is set lower than the other helms. I'm sure you'll run into some. With the new updated chain mail and greater number of compatible helmets, the variety will increase in the next update.
You guys will be happy to know that I've been working on some color variations on the tunics and gambesons. Not that many so far, but I already see it making a difference in the current build I have. The gambeson (here being the "padded cloth", since the "gambesons" are too short for the period) is difficult to retexture but I resurrected the yellow version from the old models and made it paler. This is now used by Swadian and mercenary footsoldiers.
Additionally, townsfolk, peasants, Sea Raiders, forest bandits, Rhodoks and Northmen have two new versions of the shirt/linen tunic, green and gray. Together with the white and brown, this rounds out one of the classic items of clothing of the period. I'll be giving them to some of the Western-type footsoldiers as well. I'm deliberately shying away from primary colors for these guys because some of those dyes were so expensive they could only be afforded by nobles, especially blue.
Here's how the new shirts look: