Honestly a water change that hooks to your sink is overkill on a tank that size. I don't even use mine on my smaller tanks except to refill them, and even then, sometimes I still just fill up a bucket instead to save the hassle.
You could get by with a just small siphon (I like the mini size for my smaller tanks): http://www.petco.com/product/114921/...l-Cleaner.aspx
If you are close enough to the sink you can simply siphon water right into the sink (I do that with my shrimp tank, because it sits on my kitchen counter), otherwise water can just go into a bucket.
A gallon sized water pitcher would work well for refilling.