Not to be rude, but just use google with Safesearch off.
For the nude images, you'll undoubtedly find those on NSFW sites but you probably won't have to pay for most of them if cost is an issue.
Also get Morpho: Fat and Skin Folds, study it, and eventually you'll be able to draw fat people without needing to rely on references.
Quickposes and Lineofaction are two sites that let you do timed figure drawings. You can set a lot of parameters too. I don't think body type is one though. There is a Morpho book about fat and skin folds that might be helpful in that regard for you.
It's a screenshot from Morpho.