what wireless router??

My little sister in law has a nice PC that i made for her 2 years ago but as my mother in law dosn't have much cash they aren't on the net. But my other sister in law lives in the apartment 2 floors above and they have wireless broadband. I have tried logging on ot her router but it is old and not very powerful so no joy there! What i need is a very powerfull wireless router that dosn't cost the earth as I am paying for it and I will have to mail it to Norway where they live.
Anyone got any recommendations?

Most router have that same output power, what is required is a higher gain aerial for the router, but these can be expensive also.

The router they have at the moment is a real piece of crap! What about these new super 108 ones that i have seen, are they any good?