You'll be able to export pipe delimited text files by changing the export option within your model. On the Text Files tab, specify the pipe character as the Other character ("Use the following character as the delimiter:").
You'll get the best results by modifying your ExportTable calls to use JetExportTable. See the [url="http://www.datawatch.com/pdf/products/monarch/Monarch_8_Programmers_Guide.pdf"]v8 Programmers Manual[/url] for the full syntax of JetExportTable.
Additionally, do NOT use a ".txt" extenstion for the output file, as this seems to force the fixed length text file format driver to kick in. Instead use ".csv", which activates the delimited text file driver, and the desired pipe delimiter.
Let us know how you make out with this.