I found some 2xist recently at TJMaxx that are roomier than the AE I have tried, they were thin cotton spandex and conform nicely and very soft.
If you can find any on sale or closeout try either Saxx or MyPackage brands.
Of course my default one have always been Jockey pouch with the horizontal fly.
Not sure if they still make them but the Starter brand from Walmart used to have a really nice big pouch, but once they stretched out they stayed that way til they were washed, so not good for long days, but for a few hours at a time, oh so comfortable.