Source Code Wanted - Sell me your source code

Hi,

I am looking for someone with a working system similar to or exactly like the ones listed below

1.) https://www.sage.com/en-za/sage-business-cloud/accounting/#products
2.) https://waveapps.com
3.) https://xero.com
4.) https://quickbooks.com
5.) https://freshbooks.com
6.) https://lessaccounting.com

I need a source code with SAAS capability.