MPC1 is the lowest level supported card.
It caps out at 4*10G ports.
MPC2 and MPC3 Next Generation cards are what you should be selling to clients.
If you need the older versions.
MPC2 caps out at 8*10G ports.
MPC3 caps out at 20*10G and can support some 100G.
MPC3D is a fixed port card with 16*10G ports.
MPC4 has 32 *10G.
At this price range MPC7 becomes cost effective.
MPC5 is more expensive than MPC7.
MPC7 is the latest card.
It will be more cost effective than 4 or 5s usually.
This cards MUST have SCBE2