Tracking Multiple Software Products

I am attempting to reach out to other NS users that are in the software development side of the world.  I am investigating different ways that other software development companies use NS to track 3 tiers of information for products that are sold (how many tiers that is needed may grow in time).  Having the ability to forecast or provide different sales probabilities for each tier individually as well as separately with using just 1 opportunity, but open to other possibilities in NS that may be able to provide same capability. 

Basically having 3 tiers of forecasting information without having to duplicate or triple work by creating additional sales opportunities.  Sort of like a one stop shopping place.  Example: tracking opportunities and forecasting for the software product individually which may include 3+ separate products (tier 1), forecasting probabilities for optional additional services additions that are in conjunction and cannot be sold without any of the tier 1 products across the board (tier 2), include some or all specific modules (tier 3) that work in conjunction and not sold without tier 1 but can be sold/added without tier 2 being added.  Each