Sorry, but no.... As hell.
Museum replicas and arms of valor seem to be selling cheap to not very cheap, poorly accurate to straight out fantasy stuff like Darksword and others.
Surely, one can find good stuff among it, but it's quite a search. If one doesn't know what he's searching for, he may find rubbish as well.
If there's any site to advise, there's always http://www.myarmoury.com/home.html, I guess - a lot of stuff, links to the museums and with reproductions, one usually has info about them and their level of sense.
Great site generally.
There are many good sites, but as topic is extremely broad, one will pretty much always treat about just one "piece" of it.
Such as Late roman armies of circa 400 AD.