I'd like to know it the EFIKA is limited to the use of 1 Slot RISER cards or if it's possible to use 2 Slot or even 3 Slot RISER cards too.
Think about using a VGA card together with an USB 2.0 or SATA controller card.
I can't speak for the Efika itself but the MPC5200 processor only supports 1 slot without an external arbiter/bridge chip. though you could probably make a riser card with one of ti's bridge chips on it. you would also have to work out pci slot interrupt configuration. Again I can only speak for the MPC5200 they may have put a bridge on the EFIKA board.