I am looking for humungous honkers. Like a real set of badonkers as they will get smaller and  I want to make it at least a little long (I am not making inflation hentai).  So I really need to edit their dobonhonkerlos and butts. Anyway, editing tonhongerekooger size and butt size would be so nice BUT making your own poses would be EVEN BETTER.

NOTE: Even for males plis

AR14 is great about making requested changes, but in the meantime you might want to look into the open source image editor "GIMP".  It has a lot of great tools for manipulating images, but in particular "Wave Transform" and "Cage Transform" could do what you ask.  I mostly use them to 'shift' character's weight around from one foot to the other, turn them very slightly, that kind of thing, but you can fiddle with body proportions too.  
I spent five minutes doing a mockup - attached are two images, a straight export from Mannequin and one I used Wave Transform (bust) and Cage Transform (hip region) on. This is a quick proof of concept, you can dial it in and make it look better with more time (or less extreme shifting)