Shawn, the best answer to "how can I find an agent for my 180,000 novel?" is "Good luck with that." It isn't a question of how hard it is to put down, or the fact that it isn't puffy. It could be the awesomest book ever, and you will have a devil of a time finding an agent for it if you are an unpublished or even little published author.
Let's look at some estimated word counts that might help illustrate this.
Stephen King's Tommyknockers, 260,000 words. His first book, Carrie, 60,000 words.
JK Rowling's Order of the Phoenix, 257,045 words. Her first book, Sorcerer's Stone, 76,944.
See a trend here? What people are trying to tell you is that there are no good ways to find an agent for your debut 180k novel because most won't poke a debut novel at that word count with a stick. It's a giant publishing risk in trade publishing, and a hard sell.
So, what do you do? You could forget trade publishing and go straight to digital publishers. They aren't as concerned by word count, because they don't have trade publishing printing costs to worry about. Or, you could write your next book, a far shorter book, and try to get that published first. Carrie wasn't the first book Stephen King wrote. It was the first he got published. The shorter length surely had a lot to do with that.