Be wary of a free, low quality helmet wiring kit when purchasing your helmet. PCI removes tons of these at races every year and re-wires with PCI custom components trackside for $150+.
A low quality mic and speaker will not compliment your $1000 radio and intercom investment. Low quality mics introduce noise into intercom systems and render radio transmissions inadmissible. Low quality speakers have you cranking the volume, again introducing noise into your ears. Save time and money and do it right the first time.