Hi Sadly I don't know anything about Gok's undie range but they look lovely..... Following recommendations from other MNers I've started wearing Bravissimo - their bras are great once you get used to them. I went from being 34B (M and S) to 28Ff (Bravissimo)
Ive got the sex kitten corset wasit cincher thing (like a corset but not with the top bit). I ordered two sizes and founds I could get into the smaller one (although it can be adjusted with the ribbons obviously!). I would say this product is more outer-wear than underwear (I wore it as part of a costume!).