I think the way to go with this is to put funds in escrow with a independent person and for that person to pay the illustrator for every page that was done. This way the escrow can make sure that the money is going towards a actual comic and not into some scammers pocket.
Once the comic is finished the balance can be paid to start with the printing process of the hard copies. The escrow will have a digital copy of the original comic and he/she can then give this back to the community for FREE if the hard copies are not provided within a predetermined time.