Hi Prashant
We do have text determination procedure for the condition types also in SD in transaction code VOTXN.
Here the texts will be created for the condition types under the text ID KONP in application V in Group N.
Once this is enabled using the text procedure and text ID and these entities are assigned to the condition type, the text should manually be entered in the texts in sales order (I dont remember how to do that,but I did that few years back. )
However if you want to capture this text in GL account line item, this needs be done with some enhancement from FI.