I think if I did go the university route I would be most interested in doing something along the lines of a psychiatrist, therapist, kind of job. The reason we are hesitant to go the university option is the cost and my potential lack of qualifications to get accepted.
Counselling requires a minimum of a British Association for Counselling & Psychotherapy (BACP) recognised diploma (not the ones labelled PG or postgraduate), equivalent to the first two years of a three years honour degree, with pre-degree courses. So the cost would be cheaper, but the lifetime income would be lower. Also keep in mind that you need to research inter-country transferability, should you ever wish to return to the USA. You could likely do a psychology degree in the US and then a UK BACP recognised Masters as a halfway option, to address this.
www.bacp.co.uk/http://www.prospects.ac.uk/counsellor_job_description.htmCourses in Greater London:
http://www.bacp.co.uk/accreditation/Accredited%20Course%20Directory/index.php?countyId=12The universities only offer Bachelors and Masters, and I'd be most inclined to stick with universities, although the Tavistock Centre is well-known (only Masters level).
University of East London offers the only Bachelor level BACP recognised course, as far as I can see, in London, at £10,700 per year for three years at international student fees - cheaper than most, for international student fees. Not sure how that compares with the equivalent education in the USA.
http://www.uel.ac.uk/Undergraduate/Courses/BSc-Hons-Counselling A wildcard option may be to study psychology, from undergraduate degree to PhD for free in Germany and in English - though to survive there, I'd recommend studying German before departure. It's a long road for only the most adventurous. You could do a free undergraduate degree in psychology in Germany and a UK BACP recognised Masters. This would be the cheapest option, I think, but would not address inter-country transferrability between the UK and USA.
http://www.bbc.co.uk/news/magazine-32821678https://www.daad.de/deutschland/en/Again, you'd have to work towards meeting the entrance requirements from the US before applying.
Psychiatry requires a medical degree and then specialisation. Due to the funding structure, I suspect competition is fierce and international students may not be allowed (at least in very large numbers).
See under 'psychiatry':
http://www.prospects.ac.uk/hospital_doctor_job_description.htmHope that helps.