Hi Vel,Cool idea, comic ebook.
Most of the ebook compilers will do what you want. Two issues that you didn't mention are that of security and the process for unlocking an ebook once it is purchased. Both of these issues are why I choose Activ e-Book over the others.
Everyone's needs are different, so it might be helpful for you to know mine. First, I wanted an ebook that had a couple of chapters unlocked for two reasons. The main reason is that the user knows that the ebook works on their system.
Another reason is that a user can view sample chapters before purchasing. Since refunds are not issued it is only fair that they know the caliber of the book. To me it makes more sense to have the ebook downloaded and on a potential purchaser’s computer since they are more inclined to complete the sale. I also encourage users to share their ebook with friends (that means the ebook is installed on more machines and increases the chances of sales.)
Once the ebook is purchased, I don't want the keycode to unlock all of the user's friend’s copies. The way keycodes is handled by ebook compilers is probably the single item that separates the programs.
Activ e-Book uses a system that is tied into the serial number of the user's hard drive. There is less than a 1% chance that a keycode will successfully work on another friend’s computer.
The other approach is to require the user's computer to periodically access the ebook's web site to verify that it is a valid keycode (a few compilers require internet access every time the ebook is opened). The pro side of this approach is that refunds can be issued since an ebook can be relocked. The con side is the inconvenience for the users since internet access is required.
Good luck with your ebook.