They're both good options, but I think a newer O/S is a better choice for a new pc. You certainly could use 98 however. You also brought up an excellent point: I actually do have a PCI-e video card, so I can't use 98. If anyone is thinking of using the latest, fastest video cards, then 98 isn't for you. Plus, I also play PC games on it as well, and you really do want the latest drivers for those.
As far as the OS issue, I guess that all depends on what you already have. Since we are talking a new pc - he would have to purchase an OS anyways. (Unless you are replacing a current defective pc with an OS). I don't think you can even buy 98 anymore - even through aftermarket channels.
I guess it really boils down to exactly how you plan on using this cab, and if you want a fast video card with support, or just a standard video card (which can still be pretty fast).
The possibilities are endless!
