Just to address your query about the drive being overkill - in a way, yes, because your netbook won't benefit from the full performance of the drive. That's not to say it's a bad idea at all though, and just because you can't for example get 550MB/sec read speeds from it in that PC doesn't mean it will be slow - it'll make a huge difference to the "snappiness" of the netbook in everyday usage. Buying a slower or older drive won't be much cheaper if at all, and you'd possibly end up with something that isn't as reliable or high quality. Even a smaller drive won't necessarily be much cheaper, 120GB is about the minimum sweet spot for price per GB these days due to economies of scale making 64GB drives not cost effective.
The 850 Evo or Pro would be great as suggested, the Pro as camerongray says is marketed as a higher end drive but you would be hard pushed to notice a difference in almost any real-world usage. Pretty much any Crucial drive currently on the market would be a decent alternative too - the BX100 is their "value" series, while the MX100 was their mainstream drive which the MX200 has replaced, however all three are available to buy and are equally good choices for your usage.
