Don't buy it.
With kayaks, you get what you pay for.
Good kayaks are well reviewed. Apparently
http://www.paddling.net has no reviews and neither does
http://www.Amazon.com. That's not a good sign.
If you're looking for something that's flat out inexpensive, I would look at the Coleman 2 Person Inflatable Kayak on Amazon at
http://tinyurl.com/dke62g . It's cheap, $120, and has a 4.5 star rating out of 54 reviews. Read the reviews.
Sit on tops seem to cost $800 to above.
As for me, I purchased a canoe and then purchased a Wilderness Pungo, a nice fishing kayak, although not a sit on top. Using a sit on top kayak sounds attractive when the weather is warm outside. When you're paddling a kayak on Thanksgiving day on the Chain of Lakes, trust me, you're not thinking sit on top kayak.
If you care to drive to Rutabagas in Madison, WI you can test different kayaks or canoes before purchasing. Or, rent one for the day and go fishing. You carry it from the store to the creek 100 yards away and just start paddling.
Or, go to Chicagoland Canoe Base, a legendary store in Chicago on Narragansett just north of Irving. You can't test the kayaks (no water) but they their advice is valuable.
If you lived in Florida a sit on top would be fine. You live in Chicagoland.
Save a few dollars more and get a nice kayak. You'll be glad you did.