Help required with encryption please

cjhelec

I have a ClarkeTech2000 and would like to receive spanish channels: cuarto, telecinco, antenna 3, la sexta. I have these listed on my receiver on both Astra and Hipasat and they are shown as encrypted by Negravision 3 and SECA (doesn't say which version). I understand I would need a CAM (I have two cam slots and one card slot)
I would like to know the following if anyone has this information:
1. Which type of Cam would I need to receive these channels.
2. Which of the two encryptions would be easiest for me to use.
3. Do I need a viewing card for the card slot.
3. How would I go about getting the channels once I have the correct Cam etc.

Thanks in advance!
cjhelec