Printing on pre-printed forms

Hello,

    We need to print invoices and receipts on pre-printed forms. Have noticed that this is done in report 107 and 112 but would like to know what the steps are to modify them without breaking something and keep changes for future  FA updates/upgrades.

    Basically what we need to know is how to enable/disable some fields that might not be needed like sales rep, company name or invoice text; calculate margins, fix position for fields in rows and columns to match our pre-printed forms.

    Invoces must be printed in letter size and receipts in half letter with matrix printers.

    BTW  Is it possible to create a receipt from a direct invoice ? Have created some DI's and there are no receipts, whats the workflow to create them ?

    Still cannot get to print from FA into our Canon network printer or to the local attached matrix printer in our linux test box; trying to configure them has been a headache.

    Meanwhile I'm thinking a solution using created PDF's, like renaming them like iv_01.pdf and batch printing but that's just an idea.

   Any help will be appreciated !

   Regards, Oscar.