To be honest, as long as you go for a reputable trainer with excellent reviews it doesn't really matter because once trained you should be able to use whichever brand you like and a lot of us use more than one brand as every client is different and what suits one might not suit another. When researching your course provider, read through the course content and see which seems to over the most comprehensive package (i.e., covering the theory side and trouble shooting, pre and aftercare etc) and also one that will offer support after the course has finished and also, very importantly, a course that is well accredited so that you can get insurance wherever you wish, not just by their own recommended insurer.