Newbie here (warning!)

Am taking wife to Italy in Sept '18. Flying out of Austin Tx.
Want to upgrade (miles using CapitalOne 50K+ pts or $) to Premium Economy.
What airline has best Premium Economy seats (I am 6' 3" 220lbs)?
Guidance for using CapitalOne points? Which airline(s) to look at?
Appreciate any/all help and guidance.
Thx
OG