I asked the same not long ago and was told size "L" bobbins would work. I haven't tried them yet myself though.
I've had my Juki about a year now and she works wonderfully with any thread I've tried. Mostly I use Aurifil or Wonderfil. But I've used other brands as well such as King Tut, Coats & Clark, Gutterman Glide. I've done some sample quilt sandwiches with Glide and loved the sheen of it. I have plans to use it on my next big quilt, but I'm still piecing that.
You will LOVE your machine! Oil and clean the lint out frequently and she will run beautifully for you!