When I can't decide on what thread to use, I take the threads I'm thinking of using and drizzle some on the quilt top. I just u tbread some of the thread and let it fall on the top. Make sure it falls on a coiple of different fabrics, that way uou can see if uou like on there. Also, make zure you are in good light.
That works for me every time.
Personally, I'm not a fan of the invisible threads, but that's just me.