I would also recommend a district tartan. Regarding the Orban-Prentice tartan, it is important to note that just because a tartan bears the same name as a family does not always make it appropriate for that family to wear. (For example there is a Dewars tartan which is the corporate tartan for the distillery and would not be appropriate for a person surnamed Dewar to wear as a family tartan).

In this case, the fact that the Orban-Prentice tartan is classed as a "personal tartan" and is for a hyphenated surname suggests to me that it is intended for a particular individual family, and not for all of the name Prentice to wear. I don't really have any further information on it, however. I do note that the designer of that tartan is a participant on this forum, so he may be able to provide more information.