Hello,
I have just got a bikini from figleaves online. Now, they are a bit pricier however you can order the top in bra sizes (particularly good if you have larger boobs) and then oder separate bottoms. I am a 14 on bottom and got this size by the make Freya and it is spot on.
Also, they have lots of higher bikini bottoms....some are even ones that you can fold down to suit how high you have them...I am waiting for that one to come.
I don't like the low slung bikinis and these are great...even the normal one from Freya fits very well. Comes up a nice way on the front, lovely high legs to flatter yet good bum coverage too. Would highly recommend.