Draft2Digital is much less of a pain. They'll even handhold problematic manuscripts through the process.
I'm not sure if you're affiliated with them or not, but a better model would be to charge 10% up to the cost of proofread and copyedit + a profit. Let's say these services typically cost $3,000 (like on CreateSpace). D2D could charge 10% of sales up to say $5,000 ($2k profit). If you're book doesn't hit its targets the author would still owe a remaining balance up to $3,000.