Many thanks for the pointers. Will do.
Have you tried that USB adapter specifically? I've seen on for 25 dollars and by description it outperforms the one you listed.
ALFA Network AWUS036NHA Atheros AR9271 2000mW 802.11b/g/n Wireless-N USB WLAN Adapter with 5dBi Antenna http://www.newegg.com/Product/Product.aspx?Item=9SIA8UD37Y8211