Have you seen the Mint Velvet one? I have it in the caramel they did in spring. I'm a 12-14 normally and have a big chest but got the 10 so I'd recommend trying the 12 too. It's very soft and ages well. Inhale a code for £20 off and free p&p I can dig out if you like it.
you will probably find that one that does not have pockets around the boobs is more flattering. And not a bomber jacket style with ribbing at the waist as they bunch up round your tits and chin. Speaking from experience. Do you definitely need a biker style one? If you are worried about looking butch or booby you might be better off finding one that is a bit more nipped in at the waist so it has a more feminine edge. I'm a similar build as you and have made a couple of mistakes with biker jackets.
WIT in your second link has big boobs. The leather jacket she's wearing this season is from Whistles. Their sale just started and they have a dark plum one with a lot off iirc. Loads of shops have them in atm - Topshop had a good few and again, Zara had different shapes and textures.
Do you think she does? Maybe it's just because she's so much taller and thinner than me it doesn't show so much. I love that Whistles one and it's a great reduction but I'm not sure about the colour - guess that's why it's in the sale!