OP, it really helps to define what kind of style or type of art you want. If it is individual character pieces that are affordable, I recommend using the services of
Blazbaros on DeviantArt, to whom I have referred plenty of Dakkanauts and
DCM's before with nothing but good reviews in return.
If you have the patience (I'm talking 3+ years of waiting here) and the money (this was $125+
IIRC), you can always try and get in touch with
NicolásRGiacondino, who used to go by the handle Aerion-the-faithful. However, be warned, if you manage to secure a slot, he has a MASSIVE backlog right now, my own commission took well over three years to get done.