Hi,
SO10 is not specific to any sales organization
you have to create Text for example as ZST1000 ( just as per your nomenclature) with Text ID as ST and language as per your requirement
and developer call this Text ID to invoice program or smartform based on the sales organization using READ_TEXT function module or he can globally declare it
This can be transportable as well using a report, the process is different than normal transportation
you have to use RSTXTRAN to transport standard text from development to production
you can very well maintain in each client separately as well
As a general practise, it is maintained separately in each client so if any changes required, user can manually maintain
regards,
santosh