I recently purchased a Madone 4.5 wsd - my first wsd bike. Fit like a glove from the start - the most confortable bike I've ever owned. Like others, I immediately changed the saddle. The only complaint is I'm not pleased with the Shimano 105 components. I had Durace on an Obea bike I owned a few years ago and they were great. Plan to slowly upgrade the components to at least Ultegra over the next year or so.
Don't think you can go wrong with a Madone wsd. Like you, I'm short, fat but also seriously old - 71, but I DO love how well the bike fits me.