My thought is to connect the LAN to the included NIC, and use a USB2.0 NIC for the Internet connection.
Load refers the the average number of processes running over the last 1, 5 and 15 minutes respectively. It is not related to the %cpu load.
I prefer to use a small x86 system. I really like Linksys, but I have troubles with all three devices (two NSLU2 and one WRK54G) I own. The contents of the flash gradually become randomly scrambled over time, and I can’t figure out why (static electricity?). I haven’t tried the Asus units, although I’ve heard they are very good for OpenWRT.
I like that the JrSX boots from easily removable flash memory. I really like the Soekris, but it is about $200 more.