Most of it comes down to personal preference. Like I alluded to above, there's not nessasarily anything wrong with any of the gear you're buying...
Personally, I can highly recommend the Antec P182 case, but it really depends on what you want in a case. I wanted good quality construction, low noise and good cooling. On these counts the P182 really does a great job. It also uses a pretty damned cool cable management system that feeds most of your cables (ATX power, molex power connectors, hard drive SATA and PATA cables etc) behind the mainboard tray so you don't see
any of it when you open the case. Makes it great to work on (as long as you're not wanting to pull your main ATX power cable in and out of the board - That would be an absolute bastard hehe) and helps maximise airflow. It also uses a reversed power supply which sits in the bottom of the case. The lower hard drive chassis sits down in front of the PSU and that whole section of compartmentalised off from the rest of the case meaning that all the heat generated from your drives is just sucked out the back of the case instead of circulating up past your video card and CPU. There's a lot to talk about with that case. Best to give a few reviews a look if you haven't come across it before...One point that you may not like - It doesn't have a clear side window. I couldn't care less personally but some people like showing off their UV cables, LED fans etc. Personally, to me, an LED fan just translates to a noisy fan as I have yet to see any of them that are designed for low noise. The attitude seems to be that if you want glowy fans, you don't give a hoot about noise. Either that or people just won't be willing to pay for it. *shrugs* I prefer, these days, to go as quiet as possible.
On that subject, I can also highly recommend the ThermalRight 120 Extreme...
http://www.thermalright.com/new_a_pa... aHVzaWFzdA==
I did a lot of research when I looked at heat sinks because again, I wanted to be as quiet as possible but still be able to push the CPU and keep it as cool as I can. This heatsink is damned impressive. Even at full load and overclocked to 3.0Ghz, my Intel Quad Core Q6600 never even gets that heatsink anywhere near hot to touch. And did I mention it's quiet?

It's a damned huge hunk of metal but I'd definitely recommend it if you care about such things.
On the sound card - I'm a bit of an audiophile and I have a $500 set of 5.1 surround speakers and I'm using the 7.1 onboard soundcard that came with my Asus board (the Fomula Maximus - possibly the stupidest named board I have yet seen

) and I have not missed my old PCI 24-bit Audigy 2 Platinum EX at all. With the huge improvements in onboard sound technology and audio chipsets in general these days, I find it a hard sell to justify a stand alone sound card unless you need additional sound inputs/outputs for recording etc. I used to swear by Creative sound cards but I just don't see the point in spending the money any more.
And as you've probably guessed, I'm an Intel fan myself. Again, just my personal preference.
Wow that was a lot more than I intended to write on the topic!