George,
You’ve got yourself a few unique problems here that you’ll need to solve before you can begin to think about a DCP, but hopefully we can sort through them point by point.
1) A DCP must be 24 or 48 frames per second in order to meet DCI compliance standards. From the sound of it, you may have edited your film in a 29.97 timeline with 23.98 native material. If this is true the best thing you can do is recut your film in a 23.98 timeline. It is tedious and fraught with its own complications, but as you say, converting from 24 to 30 and back to 24 will simply make your hard work look awful. No need to change anything about the resolution of your project. It will play back at in its native 1920×1080 on screen.
2) DCPs certainly can and are formatted with stereo tracks, but a minimum 3-channel mix is recommended for theatrical environments. The reason being that stereo mixes split up the dialogue between your left and right speakers causing an echo in a room as large as a theater whereas 5.1 mixes tend to bias all dialogue to one center speaker. A 5.1 mix pays for itself in the long run, but it is not necessary for festival bound DCPs.
3) There are certainly software packages that will allow you to make a DCP but they can be tricky if you are unfamiliar with the process and unfortunately may not work at all. You should not attempt to use such tools yourself unless you can thoroughly test the DCP in a screening room or theater. There is also the issue of hard drive formatting which can be particularly frustrating unless you are familiar with Linux.
I encourage you to check out our website:
https://www.simpledcp.com
to learn more about the format. We’d also be happy to advise you further over the phone.
-Garrett
Simple DCP
simpledcp@gmail.com