I recently plugged in my Dell 2000FP flat panel monitor to my amiga. I have been using the BootControl app to promote the video to VGAOnly and DblNTSC modes blindly when using the Amiga with my ViewSonic monitor.
Long story short I replaced my primary monitor (2000FP) with a larger model (2405FPW) and found that it supports 15khz modes even though its not mentioned anywhere else that it does. Either it internally doubles the scan rate or it natively supports 15Khz. Either way I am very happy since my PicassoIV died on me recently.