Limiting who can see/edit requisition UDF's in TEE

Summary

Taleo Enterprise Edition, Recruiting: Seeking best practice on which method to use to limit which users can see certain fields

Content

We want to create a few requisition UDF's which will be editable/viewable by only about 20 of our 2000 users.  I see in the system that there appear to be two ways to do it:

1)  we can create a new requisition form and file which include those fields, then associate that file to a Configuration Profile - and only those 20 people will be assigned that Config Profile.

2)  we can assign these UDF's a security level of "Confidential" and then through their User Type permissions, give them ability to view Confidential UDF's, while all other users will have a different User Type which doesn't give them that permission.