The RPLXi is being replaced by the RPLXi2. Fishing for permit in Beliize, the xp series was good. I really like the 10wt. It will be interesting to see what the new RPLXi2 is like.
As for what weight...depends on the wind, what fly, and I think...how quiet you want to be. Del Brown caught hundreds of permit on a 10wt with an 11wt line. I would go with the ten xp with a ten lie.
searchs on this site will yield much info.
One cast can change your day...maybe your life.