There isn't really any need to squinch up your image to look like that. For spherical mapping to be accurate you need to do that but then spherical mapping is a cheat reflection effect so who cares. Just take a photo of whatever you want reflected in your shiny surface and use that as the spherical environment map.
Joe is right, just create your own. For example if you're doing an outside map just draw a pale sky at the top, darker colours at the bottom and put a sun (white blob) somewhere at the top. Once you've done that throw a couple of filters over it to make it look less hand drawn and bob's your uncle.