I would only ever pay if it was like that guy in Secret Diary? haha but apparently that doesn't exist!
Probably not on Adultwork but have you seen sites like
this? I mean, he's in the US and you'd have to get past that whole "Armand is writing in the third person about his own beguiling sexual qualities" thing - but he says he's a male model and if those really are his pics, I might believe him. I'm sure I've seen the UK equivalent somewhere or other so if you just hit Google and do some searching, you'll probably find more, too. I think you could probably use some of the same tactics sensible male clients use to look for a reliable and appealing female escort: strike out any that can't spell or who use incorrect grammar; maybe avoid any who have really low rates and lots of phone camera pics of their genitals; be as picky as you like about physical characteristics and consider calling to confirm services etc.
Obviously, any male escort might still be a total berk in real life but I'd hope that a one who takes his job seriously is as good as any successful female escort has to be at transforming himself, inside and out, into the living-breathing fantasy of his client.
...Now, if only that Armand also had a degree in nuclear physics I'd probably be sending him two grand and a plane ticket right now.