I have been a member/lurker on the aliens legacy board for 4 years or more and have only heard good things about Spat's products.
You can not go wrong with a Spat or Matsuo kit for static/semi moving prop.
The next step up would be collecting all of the parts for an airsoft Thompson based pulse rifle with your choice/budget allowance of real steel parts.
Check the Aliens Legacy board for more opinions.
Mike