You don't need any static IP's (stays the same), a dynamic one would do fine (changes), but If you do get a static one, that's no problem. This is your IP that can be seen on the internet.
Even with 1 IP from your internet provider, you can have many more machines connected to your router.
They're super simple to set up, you should get all the details you need from the provider to connect, then just set up some wireless security and your good to go. If you get it from them, it may already come configured
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As far as I know, Thomson routers are very basic, but if you're just looking to get internet sharing, then it will do the job - You can probably pick one up cheaper though.
In fact, just as I was typing this, I chucked it in to google and found 2 out of 5 star ratings (can't post links as you can buy it from there) so I would consider maybe looking for a different router.
This, for example would do the trick, and more than half the price:
http://www.overclockers.co.uk/showproduct.php?prodid=NW-139-BE