I would recommend you go to a shop that has the lines and try them on your rod before you purchase. For most beginners a line that is a size or even two heavier than recommended by Rio for experts will work much better. That is the heavier line will allow you to make fishable casts out of the gate. It will not make you a great spey caster, only perfect practice makes a perfect caster, but it will allow you to fish successfully while you are on the very steep part of the learning curve. There isn't anything wrong with easy.
What did you get? I just got an Ibis for a great deal and am going to try and match it was a Windcutter 7/8/9. That is on Simon's A line for that rod. However I have been rcommended to get the B grade line which is a 9/10 windcutter. I really like tight loops and do not really like a thud when the line hits the water, so I am going to wait and see how it turns out before getting another line. That same 7/8/9 windcutter is the Simon's A line for my TFO 8wt, and it has to be better than what I have been using.