Parent & Child Products - some clarification on setup required.

I am putting together a website for a whisky seller who sells casks of whisky. They might have 8 casks of the same whisky which we'd like people to be able to buy/reserve as individual products/items however we'd like to display, on a main category page, just the one item rather than all 8, which would just look like a list of 8 of the same thing.

This isn't a stock issue because each cask has a different cask number and, possibly, strength, yield etc.

How best to achieve this keeping in mind that we're using eCart for the shopping cart application? I had a parent/child kind of configuration in my mind but can't work out how that's set up in a product table?

Would appreciate your advice. Thank you.
NJ

EDIT: So, thinking back to another project...

I should add a "parentID" field to my product table and make sure that the parent product has no value in there. The child products should then have the parent product's unique id in their "parentID" field.

Questions...

1) How do I stop people buying the parent product?
2) The customer has a CMS for products - when they're adding new products will they have to add the parent first, make a note of it's unique ID, then enter that in the parentID field for the following child products?
3) Isn't the parent product a bit of a dummy product then, or can I make the first cask the parent, and therefore purchaseable?
4) If someone did buy the parent product, which removes it from the shop, won't that remove the child products?

Thank you.
NJ