If you mean a CI card to fit into a CAM socket to receive TopUpTV or similar, Sony should be able to provide you with that information.
I have no idea why you mention MPEG4 as all the CAMs (conditional access modules) don't care whether it's MPEG2 or MPEG4; they are agnostic as far as the channel coding goes.
The ony CAMs where this matters are the Neotion ones that don't take a decryption card at all but can convert MPEG4 to MPEG2 (standard definition only AFAIK).
Edit, Jan 29th 5:15 PM
OP emailed me:
My second guess was correct.
He wanted a PCMCIA/CI compatible transcoder card like the Neotion which will transcode MPEG4 into MPEG2.
Unfortunately the Neotion units are apparently incompatible wiht hs Sony TV.
Does anyone know of any alternative transcoder units to the Neotion ?