Next iPhone, which is rumored to be announced at has predicted called "iPhone 6" 4.7-inch LCD model, and referred to as the "iPhone 6 Plus" 5.5-inch LCD model. The line-up, the same as the current iPhone 5s, three colors Space Gray, Gold, of Silver, storage size, are thought to be three types of 16GB, 32GB, the 64GB.
I do not know whether there is a 128GB model.
There had previously been some speculation that the larger iPhone model would be called the iPhone Air; however, there has not yet been any leaks which have conclusively verified either name.
Apple is expected to unveil the iPhone 6, a wearable device, and a payments platform on September 9th. We'll have plenty of coverage before, during, and after. You can follow iClarified on Twitter, Facebook, Google+, or RSS for updates. The iClarified app can be downloaded from the App Store for free!
For those speculating on the name, it's interesting to note that way back in January 2013 Apple was predicted to launch a 4.8-inch iPhone 'Math'. Looking back it's possible the 'Math' moniker was just a poor translation.