The firewire port on your soundcard may be more trouble than it is worth and therefore a good idea to use a dedicated firewire card instead. In the past I have seen loads of reports of not being able to capture via a soundcards firewire port. This is apparently down to these ports not being 100% ieee1394 complient. Try it first as it may work for you, but if you do have trouble then just put a ~£10 PCI Firewire card in the PC and use that. The card should be supplied with the cable to connect the camcorder to it as this wont be supplied with the cam.
You say you already have burning software to create a DVD. As long as you are useing Windows XP you also have good basic capture & editing software called Windows Movie Maker, but you will need Nero etc to burn a DVD as MM can't do that. Full help and advice on useing MM can be found
Here. If you want something more advanced, either now or in the future, then just do a search on the forum as this question gets asked on a regular basis and there is already loads of advice on what to use out there to be found.
As for which camcorder to get, well you really do need to state a budget as they range in price from around £200 up to over £2000. I would advise going for miniDV or HD if your budget is big enough. These formats offer the best quality for the money and are the best for editing on a PC or Mac. My personal choice of makes are Sony, Canon & Panasonic - in this order. There have been a fair few threads going lately with the 'what cam should I get' question and a lot of good advice on picking the right cam has been offered. I suggest a search to see if any of the advice already given helps you to pick the perfect camcorder for you.
Good luck,
Mark.