Hi, I can highly recommend Simone Harvey (Mind over Matter Boxing) who is based in East Dulwich.
In addition to her boxing classes she also does personal training, both individual and in small groups. I've been going to her classes and PT for over two years and have really enjoyed it. She's super energetic and motivational but makes it fun too. My husband joined me about a year ago and we often do PT sessions together with Simone, either at home or locally. Great for the body and soul! (Even if the body may intially disagree)
Her number is 07910 230296 or check out reviews on Google