For any kind of actual 'sparring' with blades, one should use blunted weapons with blades typically made of a zinc or aluminum alloy to reduce the potential for injury.
If you are inexperienced (and I must assume this if you're asking this question here), PLEASE be mindful that a sharp blade can injure the person wielding it even if not facing an opponent. To learn and practice forms, it is best to use a dull blade. Really, the only reason to have a sharpened blade is if you're intending to learn and practice cutting techniques.
Here's a link to a site that sells swords of reasonable quality for reasonable prices. You certainly get what you pay for. The page the link will take you to is for swords intended for Iado practitioners, but look around. they have a good selection in a broad spectrum of price ranges. Oh, and they look nice if display is part of your consideration (as you mention in your question).
http://www.handmadesword.com/iaido-train...
Please don't take it badly that I imply you may be inexperienced. EVERYONE is inexperienced at one point or another. Only some choose to take on the task of learning something new. If you're truly interested in learning this art, I sincerely urge you to seek out a reputable teacher.
I wish you luck.
Strict Aikido does not use weapons. Schools that use them do so for either or both purposes: to have an adjunct learning (eg, typically Iaido, but also Kendo). Or to present a frame of reference when learning the Aikido techniques. In the former case, metal katana are used (Iaido) or wooden bamboo sword (Kendo). But in the latter case, a wooden bokken is used. Since you qualified your question as not the wooden bokken, you must be referring to the either the metal katana or the bamboo - but neither are typically used in Aikido training.
So there is no answer to your question, except to say that it depends on the dojo.
Aikido typically uses the Katana and the Tanto. It may vary from school to school. If you just want a display, don't expect to use it or test cut with it. Display swords are not real swords.
Martial
The swords practiced with in Aikido dojos, what type of sword are they specifically? Not the wooden bokkens, but the actual real sword. I'm interested in buying/keeping one for display/collection.
