If you can't say it on a phone call without clarification, it's not a great choice IMHO. IE, is it .p2p or .ptwop? While this wouldn't be a real issue with early adopters and users of this forum, I still see people try to put a .com at the end of a TLD they don't recognize. Left up to me, I would definitely avoid using a number in there.
Limiting myself to the already existing list of suggestions, I like .dom the best. Then again, rhyming with .com might be a concern. For .dac, is it .dac, .dak, or .dack