Choosing hardware

[Orly]

I'm looking for pfSense box with a minimum connection throughput over 70~80 Mbps for OpenVPN with some packages (Snort, ntop, and possibly Squid).

When it comes to choosing the hardware I'm a total newbeginner, and find it very confusing to find the right parts (i.e. Motherboard which fits a dual Intel Pro 100 or 1000 NICs and CPU). PfSense mentions "Hifn, [is] capable of significantly reducing CPU requirements."

Could any of you nice folks be able to help a fellow newbeginner?

Thanks in advance!