The singing was deafening throughout, with the crowd singing most of the guitar lines too, so god knows what it will be like at Heaton Park! I haven't got tickets to Heaton Park as I preferred to see them in a smaller venue with the prospect of fewer Oasis fans.
As for what they were wearing, it was so hot in there that t-shirts were the only option I think. Ian wore a Bathing Ape x Neighborhood hoody onto the stage on the first night, but soon had to take it off. John wore basic t shirts both nights and looks pretty cool in this picture that I took on the second night I think:

Mani looked like he would have happily played naked judging by the smile on his face throughout.