I slipstreamed an AHCI driver, no result either. But I heard that I should slipstream the extended core patch on the windows 2000 setup itself, i'm not quite sure if that's true. For several times I wanted to slipstream the extended core v16a version by bwc with nLite, that would lead to a "Command line option syntax" error. Thought of trying to slipstream Ximonite's unofficial extended core v16e, it prompted me to verify the architecture, language, or service pack. After clicking ok. it proceeded to "compress cabinets", and slightly reduced the installation's size fsr, so I assumed that it refused to slipstream it if it asked me to verify, because I tested it after.
edit: slipstreamed several other drivers, including bwc's drivers, like "Intel Matrix Storage Manager 7.6 for Windows 2000(Intel 300 Series-type h) and Intel "Rapid Storage Manager 8.9g for Windows 2000 + Extended Core(Intel 300 Series), but slipstreaming the rapid storage manager specifically and running the setup would lead to an error, indicating that "The file iaStor.sys is corrupted. Press any key to continue.", then the setup is cancelled.