Your Sony lens is an 18-70mm lens. It gives you the same angle of view you'd have using a 27-105mm lens on a 35mm camera. This would be considered a lens that would cover the typical wide angle to normal range when used on a camera with an APS-C size sensor (since you have a wider angle of view for a given focal length on a smaller sensor).
The Quantaray you're looking at is a 19-35mm lens. It gives you the same angle of view you'd have using a 28-52mm lens on a 35mm camera.
Just multiply the focal length by 1.5x to see what focal length lens you'd need on a 35mm camera to get the same angle of view.
The Quantaray (a Wolf/Ritz "house" brand) is probably either a rebranded Tamron or Tokina 19-35mm f/3.5-4.5.
Your kit lens would start at slightly wider, and go longer. IOW, it already covers the same range you'd get with that Quantaray, and the overall image quality of the kit lens is likely as good. So, I'd see no reason to purchase one.
What do you mean by "would like to take pictures with heavy distortion away from the center of the image"
Are you saying you want more distortion?