I would think borders would be created in Drafting rather than Modeling since you'd need to create a view to see the curves that are Model Dependent when you're in Drafting mode with the Drawing visible. This would be different from doing a File -> Import -> Part.
If I recall correctly, if your border resides in Modeling and you place the lower left corner of the border at ABS 0,0,0 then via File -> Import -> Part you can get the border into Drafting IF you're in the Drafting mode when you perform the import. I believe the opposite holds true if you create your curves in Drafting and import into Modeling. The important thing to remember is that in Drafting, 0,0,0 is at the lower left corner of the drawing sheet boundary.
Incidentally, I used to place the lower left corner at 0.1, 0.1, 0 so the plotter wouldn't cut off the left-most and bottom-most lines and make them look thinner than the other 2 boundaries.
You can also create drawing templates and just drag & drop part files into the drawings. It's supposed to automate the process quite a bit, but not sure how well it works or how much fix-up is needed when dropping a significantly different part onto the template. That might be worth checking out as well.
Tim Flater
Senior Designer
Enkei America, Inc.
Some people are like slinkies....they don't really have a purpose, but they still bring a smile to your face when you push them down the stairs.