In steps 7 and 8 in the tutorial below, you would only just click Next if the entire disk (ex: Disk 0) you want to install Windows 8 on is already "unallocated" like in the screenshot under step 7. Otherwise, you would need to do what you posted above for step 8 to make the disk unallocated first, then select the disk and click on Next.
(from step 8)
If you want to have (recommended) the 350 MB System Reserved partition in addition to the Windows 8 C: partition on a HDD or SSD after installation, then you would need to make sure that all partitions on the drive have been deleted until it is only unallocated space. Next, select the unallocated drive to install Windows 8 on. If there are no partitions on the disk, you will get the 350 MB System Reserved.
Clean Install - Windows 8