But I need the full speed for the basic stuff like: snort, squid, pfBlockerNG, maybe HAVP, SquidGuard, Darkstat
This means then to be a fully featured UTM device, and there fore you may need perhaps a little bit more horse power and RAM
on top of this. The APU2C4 is not really powerful enough to handle that amount of things.
I was curious if that little apu can handle so many plugins :) I can max out the RAM and I would go for an SSD for fast caching.
Jetway NF9HG-2930 & 8 BG RAM & 120 GB mSATA would be nice to serve that network load, not ot much but powerful enough.
All in all ~350 Euros I would think about.