Graham, have you considered on-line POD? I have published in various formats over the years, including CD/DVD, Digital Subscription Service, protected electronic (PDFs with security devices), DTP, and conventional publishers of various sizes and strategies. Frankly, I have come to be rather fed up with all these methods.

I have discovered that a few Print-On-Demand internet based publishers (will not name any here, but there a few to chose from)– not all of them mind– can and do produce impressive results. Obvously, taking maximum control over the appearance and formatting of your project will be paramount, and some of these services do cater to that method. I find that, for myself, removing all of the argy-bargy of DTP and copies of books sat about (ad nauseum) has been a revelation.

The price ponts are a bit high, no question about that, but even so still fairly competitive given the genre you are looking to work within. At the very least, worth a look.

And what about security? I have given up on security, actually. I find that every work I have issued– in print or digital– has been copied and made available on various sites (usually in PDF, often Russian ones) for download within 48 hrs of publication. In the current realities of the internet (etc), I see no way to stop such theft. Indeed, the whole concept of Copyright seems to be dying a death just now….

But, that is a topic for another day. Do have a look at internet POD when you get the chance.