Dear Abdul,
For Option 1 you can have 2 pricing procedure for two Doc type as per your reqd and this reqd is commonly use in industry.
For option 2, I believe you can do that at sales order level as if you put any condition manually then you need to put a zero value and then use pricing type too control at billing level, I m not sure of this as I have not tested this in system but logically it should be possible with stnd system only. please check the same.
Thanks,
sumeet sah