Swamp cooler , evaporative air cooler advice please

Ok so I have a small grow tent that is about 2'x4'x6' I am running 2 90w led's and 2 of the long cfl that I think are nearly 100w a piece. At the hottest part of the day my temps are reaching about 88deg. I am considering purchasing a small swamp cooler that uses water to cool the air, also considering a small dehumidifier because the swamp cooler with raise the humidity quite a bit from what I understand http://www.sunpentown.com/sfevairco1.html there is a link to the one I am considering buying. My question is has anyone ever tried one of these,and is sowhat they thought. Also if this would be good enough to lower to temp to about 75 deg or so.
I am also considering buying a portable air conditioner but I really really dont want to spend that much if I can avoid it. But also if anyone knows of a good cheap small one let me know I would appreciate it.

no one knows anything about these?

Save your cash and dont buy the swamp cooler they are naff, i bought one and took it back it was just useless. You really arent running that much wattage so you shouldnt need either, an extractor fan and perhaps an intake is all you need.

yeah, proper ventilation can work wonders

Swamp Coolers are "Da Bomb"! But it all comes down to where you live (Do you have High Humidity or Low Humidity?). I live in a dry area of Southern California, typical humidity is 10-20% - Swamp Coolers kick ass here! And they are a hell of a lot cheaper to run than standard air conditioners. They can easily drop the ambient temperature by 20 degrees f., for about 1/5 the electrical cost of a "Compressor" air conditioner. They also add humidity to the "Air", which we so dearly need, out here.

Swamp coolers work by "Evaporating Water" through a system of recirculating water that runs over a series of "Pads" - fresh air is continueously forced though the pads, causing some of the water to evaporate. The evaporation causes an immediate drop in the air temperature and an immediate rise in the humidity. This system works very well in our low humidity area, where the water evaporates easily and quickly, back East - NOT SO MUCH!

If you live in, let's say, Georgia; your relative humidity might be 50 or 60% (or even higher). A Swamp Cooler wont work worth a shit there, too much humidity in the air! If you live "somewhere in between", with a humidity in the 30-40% range, a Swamp Cooler will work with a "varying degree of efficientcy"!

See what I'm getting at? The lower your ambient relative humidity is, the better a Swamp Cooler will operate. If you would need a de-humidifier "after" the Swamp Cooler - a Swamp Cooler wouldn't do much good anyway.