note that wireless may be less reliable than wired: obstructing walls etc. can sometimes pose problems. this depends on your house though.
as pagey says too though, you want an adsl modem+router in one, with an adapter. these adapters fit into the back of your computer. you can get usb ones that just plug in, and don't require you to take the case off your computer. not quite as good as the PCI models though, but you may prefer them.
http://www.ebuyer.co.uk
you can find good deals there. they did have good offer for a netgear (good brand) wireless modem+router and adapter combo. i would link directly but the site isn't loading for me right now.