I think it would be fine too, but the Seagate SSHD would get you a good bit more speed and still plenty of room. Seriously, stick with Newegg, OWC or Amazon for computer hardware purchases.
I'm not sure how much you want to spend, but the thing is with the 2009, you are limited to SATA-II speeds so if you went with with a Samsung EVO 250GB SSD you would simply not do better for the price, it well exceeds your disk interface limit of 300MB/s and will hit 500MB/s in a newer machine if you decide to move up and is far more durable than any spinner:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820147248
Other than that, the Seagate 500GB SSHD is going to fully rock too and is $100 less than the 250 EVO. What the speed means is faster and smoother boot ups, shut downs, sleeps, wakes, app launches and closes. Putting in a decent SSD will make you feel like you have a new computer, because in a sense, you do!
It all depends on what you want and need. If you just web surf, listen to music, email, watch movies, any new Western Digital Black or Seagate drive 500GB or more will serve you well. If you can afford it, the EVO 250 ( or 500 ) SSD will flat out blow you away even in a 2009.
Lots out there to choose from, that's for sure. You can always upgrade your computer too, 13" 2009's fetch about $400-$600 on ebay now that the new Haswell Retina's are out, so I guess you could sell it for parts with no drive in it.
My 13" 2009 with two SSD's in it is ripping fast in every respect except for the video card and older processor, so smooth it silly. But the upgrade to a 13" 2.8Ghz 16GB ram 1TB PCIe SSD drive that crushes data around at nearly 1,000MB/s.....pretty spectacular move and I needed it for my line of work.
I'm sure you will get more responses, but pick a good one and pull the trigger. Oh, and just be real careful of the flex cable for the drive, they are not hard to damage in the 2009's..