At this point I think many have given you some great ideas and nearly all have the same thoughts. First of all you have a really good body and for now keep the D7100 and than add a couple of really good zooms 24/70F2.8 and 70/200 F2.8vrII. With that said there are 3 things least important to most camera body -lens - photographer as the camera and lens combination are no better than a paperweight until used to create an image. So I suggest they you read - eat - breath photography and learn the craft. I have a great learning site on the web "kelby" search for it I think it costs $179 per year and has unlimited time it's a great place to learn. I have p---- off some people when asked what the best camera they can buy to make great photos my reply "owning a Nikon doesn't not make you a photographer , it makes you a Nikon owner" as if to purchase the best will make any one a great shooter. I do not want to sound contrary I think I've seen many over buy, get frustrated put the camera down never to grow into the potential that have.
Go learn make it fun I mean it must be fun and enjoy