I just have to remind you that newegg don't ship to Australia, so you probably need to get it from local store like umart or msy. Try staticice.com.au to look up the card you want. Both card will be bottleneck. I think will run into problem with power as well, both card use about 200w under load, and your p4 is probably around 80w so you will run out of juice. P4 is awfully power hungry. I am doubtful if the psu can handle a 5450 around 150w in max load plus around 80w for p4, gives you 230w (I think it is still not enough margin because your psu is likely to be 80 plus and you need hdd power as well). Anyone with second though?