you can plug your composite and vga (Amiga Rgb) into the lcdtv at the same time. (asuming your lcd has vga)
Run your workbench in a vga compatible mode, and play your games through composite. My lcdtv autoswitches between the two signals, perhaps yours will also.
Failng that, run in 16 colours using rebels palette and magicTV (a software flicker fixer for 4bit mode).
