When you say "authentic", do you mean an actual historical antique, or an accurate reproduction? There is a lot of pseudo-fantasy dreck on the market, but if you are looking for what they actually used, the authority on the subject is Ewart Oakeshott, who was referenced above by Ramius.
He was a scholar who devised a typeology method for classifying swords. Nowadays, when a sword is found in an archeological dig or an old collection, it is generally described by one of Oakeshott's classifications.
The sword dealers who are supplying the Western Martial Arts enthusiasts are selling reproductions which have been adapted for sparring (flexable "blunts" or "rebated") as well as totally accurate recreations ("sharps").
A couple of dealers with a good reputation:
Darkwood Armory
Angus Trim
A little lower end/ mass produced:
Hanwei/ CAS Iberia
If you are looking to drop a lot of $ on a beautiful hand-forged repro piece, I can point you at some people who do that as well. As for antique pieces, those are available out there, but I have no recommendations as to dealers.
Your comments are right on point. Thanks!
For someone wanting an accurate reproduction I’d also recommend my current favorite: Albion. It took me a while to decide to pull the trigger but I’ve finally ordered a couple of theirs. Don’t have them yet. They’re still several weeks out. One is the blunt Lichtenauer, for sparring and the other is the sharp Baron, with a period scabbard. I can hardly wait.
They’re here: http://www.albion-swords.com
I’ve handled their Lichtenauer that a friend owns, and... wow. The difference between it and my Hanwei blunt is clear. The Hanwei works OK, nothing is really wrong with it other than it’s a little whippy in the blade, but the Albion instantly just “feels right”. Huge difference. Gotta have one. :-)
Thank you for your information. However, I am interested in the real thing...an authentic medieval sword or other weaponry.
My son has quite a collection of good quality reproduction swords. They are nice to look at but just don’t turn me on much.