I think this would work for Amigas that have composite video jacks already (1200s, 600s, CD32s, others with a 520 box), as such a port is identical to those (the yellow one) used on games consoles.
The thing is, though, the quality on the composite video port is pretty awful when compared to the RGB port. I find text nearly unreadable in NTSC:HiRes.
The description says there's VGA input, but it might only be for passthrough (IE, there's 31KHz computer using the monitor already). If that's *not* the case, then a C= silver VGA box adaptor might work for the Amiga, and that would be a top-quality signal.
EDIT: I meant composite, not component. ;-)