Apple is expected to release a 128GB version of the current fourth-generation iPad, according to a new report. Like the device released late last year, the iPad will come in both black and white options, and in both Wi-Fi and Wi-Fi + Cellular versions. The report is based in part on new SKUs at a “high-profile U.S. retailer,” referring to an “ultimate” edition of the P101 and P103 iPads — internal Apple names for the Wi-Fi…