I highly doubt that the extra hyphens will benefit the users of your site, or increase traffic. I say, go with the latter
the second is more memorable, if domains have slashes etc in them it can make it a little of putting for people to remember etc. thats just my opinion.
for a micro niche then its best to get as close as possible. if your site is about kitchen sinks then kitchensink.com, net , .org etc would be best. you have just as good of a chance of getting high rankings with or without the hyphons. but the fact that you have kitchen sink in your domain would hopefully mean that in low competition { why we all chase micro niches} means that your site should rank reasonably high. don't just rest on this tho, the usual link building and making fresh keyword rich content will hopefully make you a few bucks. i have some short info i could type up and pm if your interested
I think you should look for another good name for your domain if they will not sell it. You did all you could, maybe you can get it like .org and not .com just a thought. Good luck
I think second one is good, bcoz we have seen many times googe crawl and read the sites easly according to hyphen sites...