i have had a similar request in the past. one option is to use the select-options to red the data from the underlying customizing table, in this case T301, into an internal table, and then print the contents of the internal table.
so, you would use the same select-options to first read from T301 into a table with just the storaege type in it, and this would give you the list of each individual storage type that matched your criteria. Then loop through this list and print the values...
hope this helps... remember points.
