I took him down Rikku's grid... however i'm kinda regretting it at the moment.. I sort of wish I had taken him down wakka or tidus's
However I've only just dropped into the calm lands.. so taking him through rikku's grid and into Yuna's may be helpful still. However I doubt it. By the time he gets through Rikku's grid and into Yuna's, I think I probably won't need the extra white mage by then.
Stat maxing looks like it would take an insanely long time... and money doesnt really drop that readily yet..