I can't recommend any specific surgeon for you, but I am sure there are plenty of skilled clinicians from which to choose. If you have areas of the body that you cannot improve and there is good quality skin, liposuction may be a good option for you. Seek a few consultations and you should be able to locate a competent surgeon in your area.
I'm not sure I understand what the question is. First, Vaser is liposuction. You are trying to contour your waist using liposuction and asking if you should have it in UK or "abroad"? you should actually post pictures so we can see what your existing condition is but since you did not, your only choice is to consult one or more local board certified and experienced plastic surgeons to evaluate you and your goals in person. There are plenty of excellent plastic surgeons in the UK.