Looking for a plumber

I have a leak somewhere in my wall. I need a plumber who can sleuth out where the leak is coming from. Also, one who is prudent in how much wall and/or floor he/she breaks up in order to sleuth and fix the problem. Both toilets drain into the same piping and wherever they connect, there is a leak. We see the leak at the end of the pipe where the clean out valve is. Fixing the damage the water has caused is a whole different issue that I am dreading.