Setup advice for 9.5" x 13" 8 page tabloid using 19" x 13"

If this is something you will do often I would create the document normally, with eight pages in order. InDesign lets you place another InDesign file within another, use this to create your imposition document. Make a new four page file 19˝ × 13˝. On the Parent Page make two graphic frames for the pages to be imported. Then place pages 1–8 in the new document to make your imposition. Future prints can be made by relinking to each new document.

What part are you finding cumbersome? 

I'm not quite sure what the question is. The usual way to set up "books" or other spread-output projects is—

• Keep the pages in linear, solo order in the document;
• Export to single pages in a PDF;
• Use Acrobat's booklet printing option to sort the pages into spreads/print order.

(While InDesign has a booklet option, it's... not very good compared to Acrobat's.)

But for short publications, it can be just as easy to do it as you have, with physically ordered spreads, which allow you to bleed content across for headers, footers and the center spread. You just have to manage the content flow and positioning in your head, which doesn't really get difficult until maybe 16 pages. And there's not a lot of value in having page-to-page flows in a newspaper/newsletter/menu layout where everything is little pieces.

So you can do it just like you're doing it, or rearrange it into solo pages and order and use Acrobat to sort and print the booklet layout. Not many third choices and again, for short publications, each method has its advantages.