Any penalty for keyword stuffed domain names?

I've got a keyword phrase I would like to target:

Dog training for really dumb and ugly dogs

I was thinking that I would get a domain with the phrase in it. Is this a bad idea since the keyword is so long?

www.dogtrainingforreallydumbanduglydogs.net (.com is already taken )

Obviously I don't care about branding the domain, just SERP domination.

Bad idea. Name sucks on so many levels. What is the daily search count for that phrase?

You want to make a domain and target a phrase that is searched by no one? Probably better get some better kw search information. You've done a hell of a job finding a long tail without competition but ignored the DS part of the equation. JMHO.

My keyword is not dog training, or anything related to it. That was just an example I was using. KW research has already been done. 10k/month searches for exact match with little competition. Most of the competition is not optimized.

My problem is that the keyword is a long phrase. I want to use it in the domain to give me an added edge in SERP, but am wondering if a long domain could work against me for google ranking.