I wouldnt go more than 22mm sway bars. 26-27mm diameter is too big. Even with reinforcement brackets or what not it will rip right out. Your reinforcement will be stronger than the bolt hole location.. you will find one side of the bracekt will rip the bolt right out. and you will be left with a hole where the bolt you to go.
I would stick to 22mm, 22mm will allow for some flexing.. But if you really want to have 27mm just for the sake of having them then be cautious of how hard ur cornering..One of the two bracket WILL come out... Good luck..