Hello!
I love my Juki!!
I use Aurifil 40 or 50 thread but there may be others that work just as well. Mine came with a bunch of Organ needles. I believe they are size 70 and they work well.
The only thing I don't like is my needle threader. It just won't work for me. I have a similar one on my Bernina and it works every time. Can't seem to get my Juki threader to work.