I agree on price but it seems like a nice size for me, lots of room in it hahaha
The 800D is just too big both in size and in price but looks like a tech geeks wet dream to work in. The 600T is mighty sweet but still a bit pricey and not at all what Doomsday is looking for.
That board in that case is going to be like a 5 foot person in a king size bed - floatin'! It seems like an OK board to me for a temporary setup. I haven't had any problems with anything that I have owned from Asus.
Have you tried using zip ties to hid wires behind the motherboard tray or on the far side of the drive cage?
This is why I think it's best to get air filters and live with the reduced airflow. Dust will do way more damage to a system than reduced airflow - especially with cats in the equation. The biggest killer of systems.... Smoke... but that's been discussed in other threads, lol.