Firstly, it's virtually certain that repeaters (or additional access points; one can get a straight wireless access point which is not a router) will be needed. The stuff goes through timber and breezeblock OK but thicker walls are are problem. I've seen a single wall block the signal completely.
Coincidentally this morning I have done a measurement of this, using top-notch Cisco 100mW gear in my house, and it just makes it through two block walls. The 3rd wall kills it.
A wireless access point with a directional antenna (pointing generally INTO the house) would help.
Secondly, knowing the occupation of the original poster (and assuming he does occassional work related emails from home) I would consider some serious security
He's a prime target for some high-class sniffing. WPA is a minimum here, but it doesn't work with every 802.11 wifi laptop. One could run a VPN but few "VPN" wifi routers will support a VPN to their internal wifi access point - they do it only to the WAN port.
One can't beat a run of cable for reliability, simplicity, compatibility, and difficulty in eavesdropping.