Flickering on LCDTV's in Amiga High-Res appears to be a "feature" of the deinterlacer in certain low cost LCDTV chipsets.
It's not refresh related like regular interlace flicker, it looks fine with interlaced video, actually adds a filter like effect, but it looks horrible with the Amiga.
Get your LCDTV from your local supermarket, if you are not happy with the deinterlacer, take it back, get a different model or your money back.
I've heard lots of good stories, and only one or two bad ones.