OK, what do I wear, seeing ex wit his new wife and kids?

I've already bothered yahoo with the emotional and psychological impact of seeing my ex,( he has'nt seen our kids in years and he's a total dead beat dad, kids r feaking out, so I have 2 stay strong 4 them), I need 2 feel empowered and so I reckon the quickest way is 2 look great. Here r the options,its summer here in australia, its a scorching hot day. I'm thinking one of my y but demure long flowing dresses with a halterneck and some stappy sandals,(think Paris/Lindsay tabloid shot, though I'm not a fan of either, just like these dresses), hair pulled back in pony tail, sleek looking, I've got a few tattoos and I want 2 rub them in his face,as when we were 2gether he tried to forbid me 2 have any,very controlling man. I'm an aussie size 8 which I think is an american 2/4? I'm not sure but I am small, but did pig out on pizza last night,(stressed out), so I'm feeling a little bloated. Any ideas will b appreciated and feel free 2 change whole outfit. I want 2 feel strong and y.,