Wetsuite size problems!?

[kids]

I can´t decide wich sizeto go for, used tohave a M but tried a ripcurl out and the LS felt better,butI´m worried it will stretch in the water. I´m 179 cm, 81kg, 109 cm chest 82 cm waist.

Thanks for any advice. Btw it´s the ripcurl I´m ordering.