My comment is at least semi-informed and reliable, as we own a genuine
antique katana (and 3 iaito).
First you ned to decide what you mean by genuine - antique, or just
made in a traditional style? If you get an antique engraved, katana
lovers might just hunt you down and hurt you with your defiled and
Antique blades should come with certification proving their genuine status.
Modern-made traditional-style blades can be produced by certified
Japanese smiths. Once again - certification.
Either way, there's no chance you'll be getting one for less than
$1000, whether that be US$ or otherwise.
If you are looking for a reasonable quality modern shinken (not
authentic, but good steel and reasonably forged) then you could try
somebody like Bugei Trading Company: http://www.bugei.com/index2.html
There are also good quality training iato available from places like
Tozando that are good quality, but not steel and certainly not useful
An iaito might be what you are really looking for, as they are made
for training, so reproduce the features and feel of the real blades,
but are cheaper. They can also be of very good quality, or they can be
One thing to look for is that the tang of the blade extends all the
way into the handle; not just stopping partway but going all the way
to the end. Expecially if you are going to swing it around; you don't
want the blade breaking off and flying away (and into
something/someone). If the tang does not extend, I would not trust
anything else about the sword with regards to authenticity and
It also might be worth looking for the blade you wnat first, then
looking for an engraver. I am not sure if it would be possible or
advisable to engrave an authentic blade, but maybe an iaito would be