Can anyone help me? if i bought this item... Bowens Gemini Classic 500 Twin Head Pulsar Kit (BW-4950UK) - Warehouse Express would i still need to buy a radio transmitter and would i need to buy a card and antenna for each light? I'm also buying a 250 head so would i need one for that too? Also, should i go for the c series or go for the upgrade of the r series? thanks guys.