As you can see by the comparison chart, the P45 is a performance board that supports more memory, DDR3, and more USB ports. With the new X58 boards on the market, you could probably find a Gigabyte P45 board for a low price. For the video card, upgrade to a 9600GT, low price and enough GPU for most applications and video. ZOTAC is a good brand, I have one and it has worked well.
Yeah, like I said in my previous post, why not get the 9600GT or a 4670? Why are you intent upon 9300,9400? You get GDDR3 with 9600GT which is a major advantage over the DDR2 9500GT. The 9600GT outperforms the 9500GT by quite a margin. Like HW 98 said, what are you using it for?