I would stick to the Pro if you can. If you scope search around the net there are some good reviews out there that'll give you an idea of the performance of these cards. The difference between the XT and Pro isn't all that big of a deal, but I personally wouldn't step down to the 9600 or the 9600SE. If it's a matter of 20-30$ I'd spend it to get the pro, it would be well worth it in my opinion. I want to add again that I think the 4200 is a great card, but without DirectX 9, I can't justify buying it. I already have one game that uses DirectX 9 and while it doesn't really affect gameplay (for that game, Lords of Everquest), it kind of stinks not being able to take advantage of it, especially if you're thinking about upgrading to another card for the sake of being able to play the newer games. The FX series supports DirectX9, but the performance level drops considerably for the similarly priced FX cards, I believe the 5700 Ultra is up there with the 9600 Pro though. Eagle 1 posted one review, I frequent the Anandtech site.
http://www.anandtech.com/video/showdoc.html?i=1933
Take a look around for yourself. My advice would be to spend the extra money on the Pro if you want one now, but yeah, if you can wait...