Hey there!
I did actually make a huge post about women with larger breasts, and the needs of them, when poling, but sadly I can't find it right now (argh!)
When it comes to ladies like us (I wear a 34 I or a 36 H, depending on the bra), we really need those things locked in, and most "pole bras" or sport tops are NOT going to do it. They aren't made for ladies like us, especially those in the small-ribcage, big-boobs range. Frustrating, I know!
Best recommendation would be to find a sports bra that you like. As you're in the UK, you have access to some of the brands that I've only dreamed of, out here in Canada, so take advantage of that! Sports bras can be found with both wires, and unwired varieties, as well as multiple colours, and black, and white...
There are options for us, they just... may not look quite the same as for ladies with itty bitty bits.