Looking like a nice system! I have the deluxe, and am happy with it. I also have the SonataII case. My deluxe motherboard was one of the boards that has the problem you probably read about, the faulty chipset fan. Very easily fixed, but it does suck that Asus sent so many board with the faulty fan.
As for which board to choose, I'll add some food for thought.
The A8N-SLI premium and the A8N32 both use passive heatsinks (no fans) to cool the chipset on the motherboard. This means they need fairly good circulation in the case.
The case you are looking at is designed for silence. It only comes with one fan on the back, and then empty fan brackets for you to add fans if you want to. But adding fans increases the noise and that kind of goes against the purpose of the case.
For quiet casing, there are two schools of thought. One is to minimize the case fans and be innovative about airflow. That is the sonataII. The other way is to pad the inside of the case with dampeners. That is the case I have linked you to above. It is more expensive than the sonataII and it doesn't come with a power supply, but it is a higher quality case.
2. Go with the deluxe motherboard, and if your chipset fan dies on you, replace it. That antec sonataII case is beautiful. The pictures on the website do not do it justice. I have it sitting here on my desk and it is SWEET. Replacing the chipset fan is simple to do.
No difference in performance at all between the deluxe and premium. They are identical.
But the A8N32 is a superior product. For 939 boards, the A8N-SLI series is a solid board, but not the best performer. Of all the HIGH quality motherboards, it is middle of the road. But make no doubt, it is a high quality board. I choose it for Asus's stability and customer service.
That A8N32 is an extremely high performing board, and uses newer technologies, expecially in the way the board is powererd. Temperatures are kept much lower as well.
The question is, is that board worth the premium price? My personal opinion is no. Not yet. Right now the price is too high for what you get.
I'm an happy a8n32 owner and the board come with a nice fan cooler to put on the heatpipe dissi (they suggest to put only if you have a water cooling syste..so do i and dont know if it's ok with a normal airflow but i saw many installed the same)
Just adding one more thing to all the points made.
A8N32 has x16 or 16x mode for running both the pci-e graphics cards where as the other two have 8x support if you run them in SLI mode..
so if you want SLI in your system then maybe you spend more on A8N32 otherwise the deluxe is fine as premium doesnt have active cooling for chipset, altough you will have to keep in mind that A8N SLI Dlx has a very shitty fan and HS for the chipset which you will have to change sooner or later ( the sooner the better )