Even if you're self funding, in the UK you can't just buy an insulin pump - you need the hospital to approve it unfortunately :-( You can self fund libre or dexcom without their permission. If you're trying to convince them that this would be best for you, I've found that most doctors rather like to think that things are their idea, so lead with the specific issues that you're having and then "I was wondering if a pump might help?" rather than straight up "I know my body, I've researched extensively, and this is the right treatment for me" - which is the truth but won't go down well with most consultant's massive egos.