I found some good sports bras and non-wired bras in M&S. I bought ones that were one size bigger than I normally wear (both cup and back size) and found if I extended the straps they were surprisingly comfortable to wear - and don't look too bad either.
Hope this helps and you find something suitable.
Welcome to the BCC discussion forums where I am sure you will soon get lots of good, honest support from the many informed users of this site.
To help you along I have put for you below the link to one of BCC's publications you might find helpful.