Considering the  following scenario,

• My company produced Ink and Ink is produced in batch, for example, White Ink are produced 1000 kg, at a time.

• They are packaged in various bucket sizes and quantities for sale, for example,

• • 1 kg x 30 buckets +

  • 7 kg x 10 buckets +

  • 15 kg x 10 buckets +

  • 30 kg x 20 buckets +

  • some 150 kg left are not packaged at the manufacturing time. But they can be packed into bucket later depending on stock level of each standard (1, 7, 15, 30 kg) bucket.
    

My goals are

• To keep track of

• • available quantity overall (so, how much White Ink left overall),

  • available units left of each standard  (1, 7, 15, 30 kg) bucket. 

  • available unpackaged ink

  This is so I can construct manufacturing route later on. Such as, when (7 kg bucket < 2 units) AND (15 kg bucket < 3 units) AND (unpacakaged ink <50 kg), then MANUFACTURE another 1000 kg batch

• I want to show the unit in sale order and invoice as "kg" only.
  

  So when my customer want 15 kg bucket + 7 kg bucket, I want to put manually:-
  

  White Ink - 22 kg @ XXX $ 

  instead of
  White Ink (15 kg bucket) x 1 unit @ YYY$ and
  White Ink (7 kg bucket) x 1 unit @ ZZZ$
  

  I mean, I wanna show in invoice price per kg, not price per bucket unit.  
  
  

Is this really possible, can someone please give me a hint to achieve these requirements?