I'm not certain I understand what you are trying to do, but it sounds like you want to print two copies of your booklet on each sheet, then cut them apart.
I would do this by using Print Booklet to make an imposed PDF (2-up, saddle stitch). On windows you can print direct to PDF, but on Snow leopard or Lion you will need to print to Postscript file and distill to make the PDF.
Once you have the PDF you can place that in a new document of the larger sheet size, putting two copies on each page. If there are a lot of pages, it is easier to do this by script than by hand, and the best script to do it is probably this one: InDesignSecrets » Blog Archive » Zanelli Releases MultiPageImporter for Importing both PDF and INDD Files
I'm trying to print pages as it looks in the graphic: sheet one will conatin page 1 and 3 while sheet 2 will contain page 2 and 4, etc... Since I'm using half A4 paper as standard size for my project by doing this I'll make it cheaper to print, I'll just have to cut them in half.
The problem I have comes with page numeration, I need two "actual page numbers" for each sheet.
Your document should be set up at whatever page size is a single page inthe finished book. That looks like 1/4 A4 to me. It should be laid out in readers spreads as facing pages. Each page will get it's own number.
from that point you can either use Print Booklet as I suggested earlier, or a script, to impose spreads, or you can just export single pages and impose by hand if the book is short.
Set up a new, non-facing A4 document and place two copies of each page on each sheet. For an 8-page booklet page one will have pages 8-1, page two will be 2-7, then 6-3 and 4-5. For four pages it will be 4-1 and 2-3. there should be two of each on each sheet. Print this file normally as a two-sided print job, cut apart, fold, and stitch.
Te digo como lo haría yo.
Haz las páginas normales en A5 como supongo que ya estas haciendo, por ej. usando InDesign, exportalas como pdf. Entonces te quedarán numeradas como tu las necesitas.
A continuación haz un documento nuevo esta vez en Din-A4, sin numerar y sin nada. Ahí es donde te puedes importar las páginas en pdf en el orden que tu lo necesites.
P.d. Te aconsejo que te hagas fisicamente un papelito doblado para ver bien como tienen que ir orientadas las páginas y en que orden...