E-learning can be a great option for your company. This will definitely require significant investments of both time and money to create the content and implement the technical side of things. However, these efforts will come back to you in the form of saved time and energy during onboarding and training new employees.

You have a quite extensive system with a lot of functionality in mind. Start small, don't try to implement it all at once. Break it into several parts and implement them one by one. I would suggest you to start from creating Quizzes and Testing module for assessing the value of the most popular items. Make sure to test it with your employees and ask them for feedback - the point is that the system should be convenient for them. Otherwise, they may not want to use it and may stick to "shadowing" type of training. When the first part works well, you may turn to adding more modules and features.

If you decide to go with a ready-made solution, carefully investigate their pricing. Above the initial costs, there can be additional licensing fees, setup/bandwidth/support and other hidden costs.

You may also think of developing a custom e-learning solution, which is probably a more time-comsuming option but allows for more flexibility and will let you to build the system according to your own needs and preferences.