I am looking for a product that can solve a problem for me, and I hope you can help me with this ASAP.

I have a client which needs software modules to be integrated together, the following are the modules with what I think is the software that fulfills its goals next to it:

1. Document Management System (DMS): Sharepoint Portal.
2. Company Organization Structure (needed for workflows and used in DMS also): Probably custom development integrated with Active Directory and sharepoint portal.
3. Workflow Managment System (or BPM): Nintex Workflow.

The questions are:

1. Are the points above logical, or is there something missing.
2. Will it take too much time for development to integrate the Company organization structure with the workflow management and sharepoint, or is there a simpler solution, such as a built in Organization Structure in sharepoint or in Nintex Workflow?

I am still reviewing software solutions, I am not familiar with sharepoint, a combination of software solutions which lead to this product/solution I can use as a product later on for future clients is what I am looking for also.

For example, let's say we have a Leave request workflow process, the process is as follows:

Start -> Fill Leave Form -> Approve Form by **CURRENT** active manager -> save leave form data by HR team (on file or on separate HRMS) -> Close process

The organization structure is defined, and then the "CURRENT active manager" is defined for a group of people, the process will be built by a "workflow management system"/BPM software, the "Leave Form" can be a webform, or a template stored on a document management system.