Assorted questions about uploading a flat ascii text file ported from an IBM mainframe

I’d appreciate hearing about past experiences, the pro’s and con’s, web sites, etc

I’ve been told a mixture of the following: UTL_File, SQL*PLUS, Discoverer, Export/Import, Migration Workbench (OTN), SQLLOADER, Oracle Bulk Loader

2. Parsing the fields (eg, comma or “,”). Which works best

create table customer

 ( authcust char(05) not null,
   name     char(25) not null,
   address1 char(25),
   address2 char(25),
   address3 char(25),
   address4 char(25),

   state    char(02),
   zip      char(05),
   phone    char(10),
   contact  char(25) ) 

Below is a sample of the flat file that I parsed with double colons and a comma since spaces and other characters exist.