And here's another bit of food for thought: Just because a piece dates to a specific range does not necessarily make its use in historical recreation appropriate. Take the Henry Repeating Rifle for example. At the 150th anniversary reenactment at Gettysburg, I saw a dismounted cavalryman using a Henry (there's a long list of things wrong with his impression, but I'll focus on his weapon). The Henry Rifle was designed and later manufactured in 1860, the Battle of Gettysburg was fought in 1863. Therefore, a Henry rifle is period correct. That doesn't make it's use appropriate though. Henrys were adopted by the Union Army in 1864 and on a very small and limited scale. This man saw a cool looking rifle, he wanted to stand out from his comrades and show of this cool expensive rifle, and he saw M1860 Henry Repeating Rifle and that was about as much research as he did to verify its period correctness. As such he had a really crappy impression.
The Ritter is an outlier weapon. It is not one I'd recommend if one is going for an impression generic knight of the Third Crusade. If, however, that one finds irrefutable evidence of a knight who had a weapon near identical in its blade profile and fittings to the Ritter, I'd say go for it. But only if he also adopted that particular knight's armor, heraldry, and history into his impression. If someone asks him, "What are you?" he should answer, "I'm Sir So-and-So" rather than "I'm a knight of the Third Crusade".
My overall point is this - go for what's generic, mundane, and representative as that is what we know most about. If you want to be an outlier or be different, you better have enough documentation to pull off a fool-proof persona. People will ask you questions about everything. It's a lot easier to answer questions about the average knight, or the average soldier, or the average merchant, or the average upperclass woman, than it is to answer questions about a particular person. I can tell you right off the top of my head what a typical Union soldier might have eaten, but I can't tell you what General Francis Meagher ate before the Battle of Fredericksburg. I can tell you how a particular Norman knight may have been armed and equipped, but I can't tell you exactly what Sir Wadard carried into battle at Hastings. So for that reason, I have chosen generic impressions as they give the general population a better idea of what the past was like. Some people are bored with generic impressions and can't find enough evidence to form one of a particular figure, so instead they invent a fictional personna and spread their fiction (rather than documented history) to the general and do what is called "First Person". I could go on with my deep-seated hatred for first person impressions, but that would derail the thread.
Sir Hancz requested help in a realistic (I read "generic and representative" here) kit of a knight during the Third Crusade. He has not given anymore details in that regard, so to be most representative, he would probably be an English knight of low to middle social standing. Let's face it, none of us would be able to afford the kit of a wealthy knight. As a soft kit goes, he should stick to bright contrasting colors. His surcoat should be monocolored with the main color of his blazon. The helm may or may not be painted. A gambeson would be acceptable, and the maille should be fairly standard flat wire with dome rivets. It should have integrated mittens and coif with ventail. The shield should be a flat-topped kite shield. The sword can either be an early Type XII or a late Type XI. I'd go with a Type XII personally. In portraying a generic role, he would be able to give the general public a more holistic view of the Crusades experience, than if he was portraying one particular outlying knight.