Kevin,
There is no use of using Std. SAP Purch Regist (J1IPUR) & Sales Regist (J1ISAL).The most important reason is that they are at header level not item level.
I'm testing both these reports and found that they are at header level only. We want these reports at item level. Have you come across any OSS note/ BADi where we can make these reports at item level?
Thank you.