Well, there is The Portrait Portal - http://www.karwal.dk/portraitportal/ - you could try. As far as I know, they don't ask for money, but patience, since there's lots of requests they get. And since it seems Aklon is not in the "gold" stage yet, time shouldn't be in short supply.
The site, beside the high-quality portraits and no remuneration policy, has another thing to recommend it - it's done this kind of job before: JCompton had a custom portrait made for Kelsey there, and the nice Jude Law picture is in fact a custom work for the apparently now retired Neh'taniel mod (involving an undead elven Judicial Knight of Amaunator). Just ask, please, Kasten Dahl (the artist making the custom portraits) to use the "standard" BG2 look / paraphernalia instead of the new, more realistic (and less baldurish) one.
OR, you could use a modified Balthazar portrait (if your artist can / is willing to work with it) -> it has the benefit of seamlessly blending into BG2 and being made especially for a monk, but Aklon will have to shave his golden curls...
