Dual WAN is a strength of pfsense, so it would really be the best if you don't mind the troubles.
The budget can be as low as ~$1500, depending on what you want to have,
very often an entry grade Celeron with Sandy Bridge or better micro-architecture for 1Gbps WAN, or D2500/D2700/AMD E-450 for 500Mbps or below, 4GB or more RAM,
a 4GB USB Flash drive, an lan card with Intel NIC (82574L/579V are fine)(e.g. Intel EXPI9301CT), a gigabit switch
finally a motherboard with Intel NIC (intel boards), and case+PSU. You don't need a harddisk unless you are hosting server.
You can surely use other NICs, but be aware of the compatibility with the OS, depending if you are using ClearOS/pfsense/others.
The sum shouldn't exceed $2000, and the best if you can make use of old parts. In HK the problem is only getting the suitable lan card with a reasonable price......
Dual WAN, VPN are fine for both OS.
Copying files should be very fast as long as you get a Gigabit switch.
Not sure with ClearOS, but pfsense has no support on even 802.11n owing to FreeBSD doesn't support it. But you can just add a wireless access point to get the WiFi online.
[ 本帖最後由 ccw 於 2013-9-2 21:13 編輯 ]