Harper / Gabie is one of my best shags ever, including very good DFK, but she's now £600, so totally out of my price range. If you're willing to spend that kind of money, she is truly fantastic
https://www.ukpunting.com/index.php?topic=314878.0Camille is very well-reviewed, but in a similar price range (£500)
The ebony Naomi Van Cartier gives an excellent DFK, one of the best (the second time I saw her it was even better than the first one I described in my review)
https://www.ukpunting.com/index.php?topic=291552.0The DFK is as good, if not better than Harper / Gabie. The overall experience is very good but not as mind-blowing; however, at £250, Naomi is much better value for money: with the same money, I would much rather see Naomi almost 5 times than Harper twice.
They are both mid-to-late 20s, more than early 20s - not sure if this is a dealbreaker for you.
Thinking of ladies who are not available right now but who might come back:
The ebony Sophia / Elle was one of my best shags ever, too, up there with Harper
https://www.ukpunting.com/index.php?topic=290994.0This one provided a very good service but I doubt she was early 20s:
https://www.ukpunting.com/index.php?topic=332751.0Naomi gave a great service, a good but not mind blowing DFK:
https://www.ukpunting.com/index.php?topic=329641.0