"b" will be fine for what you want. A network with an 11Mbp/s speed is plenty to just surf the web with considering you are only connecting at 1Mbp/s. You only really need "g" (54Mbp/s) if you are wanting to stream videos accross your network.
With regards to connecting your laptop via ethernet cable for downloading music, dont' bother because you will only be downloading at roughly 1Mbp/s which as I mentioned above is much lower than your network capacity at 11Mbp/s.
Hope that helps.