It's counterintuitive, but padding is not usually the recommended solution for your problem. If you can put pressure directly on your sit bones without the padding pushing back against your soft tissue that contains nerves and can restrict your circulation, you'll be better off. Brooks, Selle Italia, Velo Orange and a few others make stiff leather saddles that, when broken in, conform to your butt shape. Also, the design is more like a hammock, that - while apparently stiff - actually has more give than a standard plastic-frame gel seat. The Brooks B17 is the most common of this style...it's what I have and I was skeptical at first, but am definitely now fully converted to the cult of leather.

If you do want to go with a wide padded seat, you need to use a bike that's designed to be ridden from a more seated position. A Dutch-style upright bike. They are slower and less efficient, and thus less common here (because our car-centric cities make most commutes fairly long), but generally regarded to be more comfortable.