How well do you fly your trainer?

Based on that answer, i would recommend

either:

1) the Avistar Arf -- with a 40 size engine, semi-symettrical wing, so it is a bit more acrobatic

or,

2) 40 size, the great planes Easy Sport, mid wing, still has a dihedral (sp)

or,

3) 60 size, the Sig Four Star, low wing, great plane and bigger so more stable

All good choices, and each with its own merits

Steve