I got the sunset from Sealife. It's now feeding on live brine. It did try on pellets and mysis but it spat out but i'm still trying to train it to feed on pellets or mysis at least.
As for the sunburst, i did notice some similarities from what you mentioned, it does shy away alittle from the sunset. But i thought i saw it eating the brine as well.
fingers crossed for now..