It would be a shame to have to cull these boys. I use Craigslist successfully. Really great photos, like the ones you just posted, are important. You can also keep renewing your posting every 2 days, to keep your ad at the top.
If someone sends me a response, I ask for a good contact number, and if they do not respond, then that is that for them. Sometimes people are fishing for your personal info, so if they respond to your ad with a vague "do you still have this/it available?" then I do not answer them. Once you find someone you think may be reliable/serious, then you meet at a neutral public location like a gas station parking lot. Do not give people your address. Also I do not recommend giving them away for free, even a nominal fee will weed out most of the crazies. Good luck, I hope they can find homes soon.