This is what I have and it works extremely well. It's the smallest portable a/c unit made as far as I know, and that means less energy consumption. It raises the bill about $20/mo. running non-stop in the middle of the summer with the lights on 12/12.
I have a SunHut tent which has a giant 'U'-shaped back flap that zips open, so I just push this a/c up to the back of the tent so that it blows into the tent, but draws air from outside the tent. BAM! instant intake fan as well (and the intake air is filtered). You just have to seal up around the unit good once you have it positioned to keep the cold air in and the light out.
It cost me $400.00 plus shipping when I got it 2 years ago. They've come down some since then. Target has a pretty good model for $300.00 I saw recently. But mine has been running for 2 years non-stop and still works like the day I got it, so maybe check out Amcor? Here's mine:
And here it is pushed up against the back of the tent like I was saying. (Kinda hard to see...)
And here's where the exhaust ends up going (the lower hose is the a/c, the upper hose is the light):
And finally up and out into the attic.