<<< but there doesn't seem to be away to import it into publisher >>>
That's correct; Microsoft Publisher will not open Adobe Acrobat PDF files. Bill's option to try fiddling with the n-up function could be one way to go.
However, I had a really bizarre thought just now ... pretty left of center actually .... but I just tried it and it worked. Are you running Acrobat 6 or 7 by any chance? My bizarre thought is to use Acrobat's watermark feature to accomplish what you want.
First, make a blank 11 x 17 document in Word or Publisher or whatever and print it to PDF. this becomes your base document into which you are going to watermark the other two PDF files.
Second, with your new blank 11 x 17 PDF open in Acrobat, select DOCUMENT > ADD WATERMARK & BACKGROUND. In the resulting dialog box:
for type TYPE section, select Add a Watermark
for the SOURCE section, select From File and then navigate through BROWSE
for the first of your original two PDFs.
in the POSITION & APPEARANCE section, select a HORIZONTAL ALIGNMENT of Left
When you click OK, you should see the first of your 8.5 x 11 PDFs conveniently parked on the left side of your 11 x 17 PDF. Now do the the same steps again, this time using the second of your original PDF files and changing the horizontal alignment to Right this ttime. You'll end up with an 11 x 17 PDF document that shows your previous two 8.5 x 11 PDFs side-by-side.