Mimo if you want good range, don't touch the draft-N or 802.11n hardware yet.
Belkin MIMO routers are your best bet, the range is great as this has 3 antennas to boost signal.
http://www.broadbandbuyer.co.uk/Shop/ShopSearch.asp?CategoryID=331
ADSL versions
http://www.broadbandbuyer.co.uk/Shop/ShopSearch.asp?CategoryID=269
Cable versions.
Otherwise just get any wireless router with wireless USB adapter or wireless laptop card or wireless PCI card. Netgear or Linksys or Zyxel will do you best.
Then add a DIY range booster to any wireless device that has a antenna.
http://www.freeantennas.com/projects/template2/index.html
I own a Speedtouch 585 v6, for it's rock solid firmware and stability. Though the web interface is not user friendly!