I think you will find that VHS tapes look terrible on a
computer monitor, but may look about as good when played
back on an old SD CRT (typical older) TV set.
All you need is any card with an S-Video input, and it
should come with an adapter if you need to convert from RCA
jacks on the VCR to the S-Video. There are many choices in
cards, some with only the S-Video input and others with TV
and/or radio turner, some onboard a whole video card. It
really depends on what you want including whether it would
be AGP, PCIe, PCI, or USB. The USB types tend to make MPEG
while the others allow more versatility in the codec you'd
use, though of course DVD is also MPEG(2).
They are all fairly equal in video quality for your
purposes, how you choose to encode it will be the other
factor and that is something you have control over
regardless if which input card you choose - except for the
USB type as mentioned above, you would need to re-encode if
you wanted another format.
The entire topic of video capture, editing, etc, is really
too broad for a single usenet post. You might want to go to
Newegg.com and seek capture cards, reading the user reviews
for any that catch your eye.... but keeping in mind that
some people will want and complain about some features that
won't matter for your purposes especially when talking about
TV tuner type cards since you won't be using the tuner
features at all.
