I hear good things about the Apex kits. If you are not mechanically inclined, you may want to find someone who is. The Sigma series are pretty simple, to me, but I am a factory trained armorer on several different platforms.
The VE series are inexpensive guns. Reliable and accurate, but the triggers are betond terrible.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball