The wizard will only show options if there are free drives to configure. With 4 unocnfigured drives it's simple to make a R5 LUN and the wizard will also put an HFS+ filesystem on the LUN.
The Images show that in Luke's case, there are three drives and they are already configured. The wizard won't work on configured drives, it's job is to make the initial configuration of unconfigured drives simple. It is not designed to change the configuration of drives that are already configured.
Regarding Alfred's case, the Wizard is the wrong tool for the job. Go to Background Activities and choose migration.
The command from the CLI is...
migrate -a start -d 0 -l "id=0,raid=0"
This assumes arrayID=0 and LogdrvID=0.
Be advised that migration can be slow, make sure the MAC does not sleep.
Also, RAID0 is not recommended. If any drive fails bad things will happen.
The way to make the disks unconfigured is to delete the LD and the array. If you have your data backed up or don't care if the data gets deleted then it would be a lot faster to delete the LD then the array and create a new volume. If the Wizard is used the Advanced option will have to be used to create a RAID0 LUN.