It was recently reported that Rory MacDonald vs. Hector Lombard is being targeted for UFC 186, so now we've got 2 options.
OPTION #1: We find some guy on the regional circuit who will take any opportunity he can to get into the UFC, a Latifi scenario, and we watch Brown (likely) kick the shit out of him.
OPTION #2: This is my personal favorite, we pull an already established UFC fighter from an upcoming fight to take on Brown for the main event.
a) Brandon Thatch or Stephen Thompson @ UFC Broomfield
b) Jake Ellenberger vs. Josh Koscheck @ UFC 186
You've got guys like Magny fighting on that card, and I'd prefer him over a newcomer, but preferably I'd like one of the 4 guys listed.
If it were up to me, I'd choose
Josh Koscheck for multiple reasons.
1) He's fought 5 rounds before when he fought Georges St-Pierre for the title.
2) His title fight against GSP & winning the Ultimate Fighter and coaching TUF alongside GSP have established him as a name that people recognize and will tune in for.
3) He's on the decline off his career, and it's sad to say this, but he's expendable.
4) Thatch and Thompson getting thrown to the wolves this soon is probably not the best idea. Ellenberger hasn't looked good as of late, but he's probably got more in the tank than Koscheck.
5) Despite likely being the underdog, stylistically, it's not too hard to picture Koscheck winning this. He's still a great wrestler and hits hard, he could try and grind away a win. It wouldn't be pretty, but it could work.