Hi ZeusSE,
For this issue, first, please debug the code to make sure that you have created the custom field successfully, try to create a column based on field type in a list from UI, check whether the field type is shown
in create column page, and can be added as well.
And from the picture you provided, fields type shown in it is not all of existing field types, some types may be not available in this situation.
More information, creating custom field in SharePoint 2010:
http://avinashkt.blogspot.com/2011/07/creating-custom-field-in-sharepoint.html
Thanks,
Qiao
Qiao Wei
TechNet Community Support
