Generally speaking circumcision is only undertaken in adults for health or religious reasons (though even still the reasoning for having it done due to religion is an abhorrent excuse for genital mutilation). You’ll find it difficult to find a healthcare provider who would do it based off of aesthetics, even cosmetic surgeons would advise against it if it was not totally necessary for a health of hygiene reason. You would certainly not get this procedure done for free on the NHS, unless there was a genuine threat to your health.
Circumcision at any stage of life comes with risks, most notably the reduction in sensation from the penis.
Circumcision is essentially removing the protective layer over the sensitive glans - this is uncomfortable post-op until the time in which it eventually dries out, often reducing sensation. You risk reducing the level of pleasure you feel during intercourse and masturbation, resulting in long term complications when with a partner.
If pursuing this procedure is purely motivated by aesthetics, please reconsider. As it is not for any real health concern, what you are pursuing is genital mutilation. As a society we are so against the mutilation of female genitalia, so why on Earth do we idolise it for men?