But... but... I thought Macs were secure? (evil grin)
If NATting alone makes you feel dirty, then try the MIMO Linksys routers. I've had fewest wireless problems with the useless MBP's (and you may have better luck with the MB) with the Linksys MIMO routers. The WRT600N is the functional equivalent in terms of connectivity of the Extreme with 4 gigabit ports, MIMO wireless and USB storage sharing capability, but it is not Time Machine compatible (you can make it compatible, but I wouldn't recommend it). It does feature an SPI firewall.
I don't like the Drayteks. I've had various iterations for use in branch minioffices I have after recommendations but they used to crash on a uselessly regular basis, like once every month. These days I go Linksys or straight up to Cisco / Check Point / Juniper / Fortinet. The Drayteks are more feature-loaded than basic home routers, but they're useful only for those people who need the features and actually have more than a slight clue what they're doing, which I think excludes the vast majority of Apple users 😛