If this box has compoment and no COMPOSITE then the picture you will get it will be very close to RGB. So just get it!
If it has composite or SVideo then the quality will be bad..
Compoment and composite is a very different signal, svideo is close to composite signal , you can make an composite from sv by joining the 2 wires from H sync and V sync together. Also the amiga does not have Svideo avail by default so by making an adaptor to create svideo from composite you will not gain much quality if any. Amiga also does not have compoment but you can create this signal from RGB. If it is to rate the signals from 0 to 10 then it is as:
composite 2
Svideo 4
Component 8
RGB 10
