Someone above mentioned the cutlass -- it may be something worth looking into. It was designed for close-combat with limited space to swing (because of all the ladders, ropes, etc, on a ship) and designed to be used with relatively little training and almost no footwork (because of the pitching, swaying deck). Most sailors spent their free time practicing with cannons, or their ropework and sewing, so the sword evolved to fit that type of lifestyle.
I would find a short, heavy blade that is relatively straight. (cutting and thrusting) They are more for clubbing with an edge than the slicing action of a katana. Also, if you get a pair, they look really cool when hanging crossed on the wall. (I have a cavalry saber [useless for self defense, BTW] crossed with a sharpened live-steel cutlass on my living room wall). It keeps it handy for access, in case you can't get to your gun-safe in the bedroom, but most people think it's a decorative wall hanger, and aren't threatened by it at all.
They are also relatively short, and since the design was originally a sort of lengthed bowie knife, your training should give you a good foundation for the footwork and strategies of the cutlass.
However, be aware that the cuts are thrown entirely different. You have to bring the tip of the blade behind you to get any speed up, but you have, have, have to keep your hand (and more importantly, the guard) between you and your attacker. Otherwise you leave yourself wide open whenever you throw a cut. It feels awkward at first, but you get used to it.
Feel free to PM me for more specifics on the cutlass, if you want.