sdub I bought my first kayak Monday of last week at Academy. They had a sale on the 8 foot sit-on-top orange "Sunbeam" kayaks. These are made by Pelican, although this fact seems to be well hidden and not listed on anything except the boat plug and in the owners manual. Academy had them on sale for $130 down from $200. For me I just wanted to get off shore so this was a great option. I've taken it out twice and have been pleased so far. The model is kind of the barebones model, so you will want to do some self rigging. Today I added some screw eyes to add some bungee cords, and rigged myself up an anchor out of some parachute cord and a 5lb weight from a weight bench. Its not luxury or roomy, but it sure as hell works for me, and is relatively stable (although I don't have much to compare it too).
here is a link to the kayak on the pelican website, the sale was designated for last week, but they may still have them on sale.
http://pelicansport.com/index.php?language=en&category=kayaks&nauticalboat=burstthe one at academy comes with a seat already rigged up.
hope this helps, i know you said sit-in, but for a first time kayaking college student on a budget such as myself this was a good buy imo.