When you can't seem to decide which instrument you are going to purchase to use for your concert or even at home, then I guess the best way for you to do it is visit your local music store. Although you can find lots of sale items online, you can also check at the store if you want to be sure of its features or specifications. After all, you are the one who is going to use it. And it would be such a waste if you regret buying something that doesn't suit your taste.
And I always believe that you can still find affordable and great instruments at the local store near you. So, start shopping now!