Upgrade old laptop with SSD

[Keith Smith]

Hi,

I have an older laptop.  Not sure when I bought it.  I'm thinking I 
bought it before 2009, however the CPU is an AMD 3300M which according 
to what I am reading was not in production until 2011.  It has 4G of RAM 
and a 500GB HD.  It's running Win7, which is a little slow.

I was thinking of replacing the HD with an SSD and potentially making it 
into a "Chromebook".... (Thunderbird/Libre Office/ Chrome Browser)  I'm 
reading the SSD's are 10x faster than the HD. There has been prior 
discussions about breathing life into old hardware by replacing the HD 
with SSD and installing Linux (now we are on topic).

Initially I was thinking a small SSD since I will probably never use 
this laptop in production... But you never know.  If these mods work out 
I might dual boot it - Win7 / Mint 17 KDE.

Newegg is selling a 240G Kingston SSD for $65 which is probably way more 
storage than I would ever need. 
http://www.newegg.com/Product/Product.aspx?Item=N82E16820721108

What type of lifespan should I expect for an SSD with moderate usage?

Anything specific I should be looking at?

Thank you so much for your help!!

-- 
Keith Smith