How to create a Child field - Potential and in General?

I just wanted to check on how to create a child field for potentials module.

Basically we use this module for our quotes system, we have thousands of variables in our stock so creating a products list is out of the question for us.

Basically when we quote there could be MULTIPLE quotes, what we currently use is a basic format in which i created an auto number quote field so that each quote get's it's own number.

For instance:
quote no. 345 purchase (new), £**,***
quote no. 346 lease hire, £**per week
quote no. 347 contract hire, £**per week
quote no. 348 purchase (2nd hand), £*,**
quote no. 349 purchase (refurbished), £*,**

So for us on this occasion we supplied X Company the above quotes, if they wanted to look at pricing for every option available this is basically what we would supply.

I had thought of incorporating this into one quote but this looked too difficult when starting out so i just kept it all separate. But now i am thinking that there may be a better way of doing this.

I just want to link them all to the same instance of quote as each one would need to be closed off, to act as a reminder to close the others as well. We seem to have got into a habit of just selecting close won on whatever has been chosen but not done anything with the rest so they look still look they are open quotes.

I would assume that i would have to use look up but add several of these fields?