You should do a search of the specific model number of the laptop on Amazon and make sure the listing shows your model number. As long as its got that you should be fine.
Post up the number here.
I used to sell a lot on eBay too, but I got tired of all eBays bullshit and getting ass-raped with fees.
Amazon is a good place to buy but like I say, make sure you know where your product is coming from.
Be careful when looking at cheap products too because there is ALOT of cheap crap on the Internet coming out of China. Most of the time the sellers do their best to hide this.
Stay away from eBay... Just out of principle.
I fucking hate eBay.