Dropping the saddle nose will cause additional problems as weight will be transferred to the shoulders, neck, triceps, wrists, etc. Sounds like you want to make a difference in your lifestyle and that's great. I suggest that you look for a bike fitter (maybe BikeFit fitter) and let them adjust you properly. Don't buy anything or do anything as a proper fit will do wonders. As the weight comes off positions may have to be modified and the fitter will take you all the way. Look up:
http://www.bikefit.com
Get fitted and it will be the best thing you would have done for yourself.