Lands End is a great on-line source. They have fabulous customer service. Even if you are doing everything on-line and then have a question, you can call their 800 number 24/7 for extra help. You can purchase pieces separately. Although the bathing suits are not cheap, they are extremely well made and will last a long time, even when being used in heavily chlorinated swimming pools. Also, they don't "expose" you when they get wet:) I have been purchasing Lands End swim suits for 20+ years and highly recommend them. In addition to being able to purchase tops and bottoms separately, they have a great selection of styles. Good luck!