yet another swimsuit post from me!

I am looking for a swimsuit top (not a tankini) that has LOTS of support for a large chest (I am nursing a six-month old and will be nursing all summer).

Most of the tops I have found don't work because they have a hook and eye closure in the back instead of a tie. This doesn't work because my waist is still small(ish). All of the tops that fit my big boobs are too big around the waist!

Does anyone have a suggestion for a supportive swimsuit top for large chests (not triangle style) that will fit a narrow frame?