I have got the Official US NTSC Version, it works good, but only with NTSC VCD as well as XVCD.
Victor made one, as did Hitachi, however id steer cleaf of any other brands as they are crap
Another thing to be aware of is that the Hitachi card is a twin operator, that is, it operates with PAL and NTSC as well as Photo CD.
HEad over to www.gamefaqs.com for a good FAQ about the Saturn VCD cards as well as the XVCD format. There is also a page called "Assembler" that has a good section about how crap a no-brand VCD card can be, i think that the URL is...
I Just looked at Lan-Kwei (www.lan-kwei.com) and they had a third party one, that i would steer clear of. Gamechoice club seem to have one. (www.gamechoice.com.hk), however it is a victor one, but these are still good. The model number is RG-VC3. I'd check it out in that FAQ first to make sure it suits your need, but i think that it is a twin operator card.
I have dealt with lan-kwei before and found them to be a pain in the ass. I havent dealt with gamechoice before, but whenever ive emailed them, they've been quick with their responses.
Other than these sites, you could check www.ncsx.com or Ebay, but beware of shitty cards on ebay.