Skribs, I'm no swordsman - not even kinda-sorta - so I'll pitch in with all the expertise that statement indicates.
I second the comments others have made about full tang and wrapped hilt. Those are things you want - they'll make your kata easier, and you'll look better doing it. I fully understand (though I don't participate in) the fun of what I call "flash kata": kata that aren't being performed so much for learning effective combat, but for the aesthetics of them. While Chris is right what you're looking for isn't technically an Iaito (because you're looking for something less accurate to a combat weapon), that's what I'd call it (incorrectly), and a name you might find used for it on some of the mass-market MA gear websites.
The full tang will balance the weapon better, likely making it faster, in spite of the added weight (weight at the far end - actually, proportion of weight at the far end - matters more than total weight). A wrapped hilt will make your grip much surer, which should make your transition moves smoother. Get those things, and look for lighter weight (similar principal to the fiberglass staff) overall, and you'll probably be happier with it. I'd probably even put those three items as more important than the overall length, though that might be a mistake, since I haven't even seen the kata you're planning to use it for.
I second the comments others have made about full tang and wrapped hilt. Those are things you want - they'll make your kata easier, and you'll look better doing it. I fully understand (though I don't participate in) the fun of what I call "flash kata": kata that aren't being performed so much for learning effective combat, but for the aesthetics of them. While Chris is right what you're looking for isn't technically an Iaito (because you're looking for something less accurate to a combat weapon), that's what I'd call it (incorrectly), and a name you might find used for it on some of the mass-market MA gear websites.
The full tang will balance the weapon better, likely making it faster, in spite of the added weight (weight at the far end - actually, proportion of weight at the far end - matters more than total weight). A wrapped hilt will make your grip much surer, which should make your transition moves smoother. Get those things, and look for lighter weight (similar principal to the fiberglass staff) overall, and you'll probably be happier with it. I'd probably even put those three items as more important than the overall length, though that might be a mistake, since I haven't even seen the kata you're planning to use it for.