Just a couple of points. First as has been suggested before something within the parameters that you describe is going to probably be rather unweildy. This is not to say that it couldn't be done but I'm sure you would probably want something that you could use. I have heard rumors about chinese "horse choppers" and so forth but I would suggest that 10kgs (22 pounds?) is far to heavy for a reasonable sword. Historically most "great swords" probably didn't weigh much more the 4 or 5 lbs. Also a metal sheath (unless you are planning to line the inside with something) is going to mess up the polish on your blade.
Here is what I would suggest.
1) Do a lot of research. Although a new design may be very good typically the old designs are combat evolutions. Ancient swords look the way they do for a reason.
2) Talk to a smith, many smiths specialize in one type of steel or another. They will be more comfortable working with that steel and you will end up with a better sword. In my opinion you should avoid any stainless like the plague. Steel like 1086 or 5160 are about as good as it gets with proper heat treatment.
3) Be prepared to shell out some serious money. A good custom sword is expensive. I am sure you can even find someone to build the thing that you propose now (although after a little research I doubt you will want it) but something like that will cost you and I'm pretty sure you won't be happy with it.
4) Here are some names:
Howard Clark - makes custom katanas - not accepting orders right now but probably will be by the first of the year.
Randal Graham - might be your best bet, he likes an interesting new challenge. You have to work with him though.
Don Fogg - makes Chinese weapons as I recall
Kevin Cashen - beautiful pattern weld stuff
Al Massey - mostly leaf blades and basket hilts.
Tinker Pierce - excellent custom maker but overloaded right now.
5) Here are some links:
www.swordforum.com www.netsword.com
They will help in your research.
Good luck.
[This message has been edited by Triton (edited 09-29-2000).]