Hey Helen, your best bet is to call a few companies and go to a consult, then you will get a general feel for which one you like most. I had consults with the Harley Medical and the Hospital Group but ended up choosing with MYA, can’t fault them, great experience, really supportive and were least expensive (bonus!)
After the consult, if you are still keen, they will give you a consult with a surgeon who will talk you through potential sizes etc. My advice then is to come on here and see what other people say about sizes, profiles, unders overs and so on and then you can make an informed choice. sofeminine.com is also a good site to learn about it through everyones experiences. Good Luck xxx