Gear via postal should be no worries at all. Replicas however I'm not so sure about, buying from airsoft stores abroad they come through just fine. What I'd be careful about is greengas, CO2 and batteries. You might want to check with the postal services you are concidering using and ask them directly, if the thing you want to ship are allowed and as to how they should be packaged. If possible I'd recommend using hardcases for any replicas, li-po bags for li-pos and li-ions and to mage sure all gas mags are depressurised before shipping and mags out of the replicas. Those are the most common things I've heard about traveling with airsoft gear.
Hope you and your gear make it here without a big fuss, do let us know how it went, so we can provide better advice in the future, should anyone need it.
