It's a bit tricky... this might not be the same one as some of us here have. It looks the same externally, but you never know.
Yes, as said you will need an RS-232 cable, mine came with it, but even though the cable is pretty standard - there are several standrads, so it would be easier if they just sent you the cable rather then you trying two or three different ones.
As for the software, again I would expect them to [provid e adownload link - if it is not the same as the one we had then the Hungarian software may not work with it..
In short, you can either paly it safe and buy it from the same ebay sellers that we got ours - though it's about a tenner or so more, or you could be adventerous and buy this one - if it turns out it is not the same as the one we have, then you may be lucky and actually strike a better one....