Looking For Solicitors in London

The father of my children and I divorced over five years ago.  It was an ugly and messy divorce and the children were really affected by the drama.  I wish it could have turned out differently, but their father made it impossible to be civil.  He was ordered to pay child support and was granted liberal visitation rights.  He rarely sees the children and only sends money when he feels like it.  I really don’t want to take him to court over the support issue but I will if I have to.  I am going to find solicitors in London that can recommend the best way to proceed.