Probs with variable products

Hi, not sure if this is the right forum to post in so please excuse or re-direct me.
Having trouble getting my head around adding products using product variables.
To explain, my products are motorcycle parts.
one product fits many models and the only way I can figure to list them is using variables.
this is not great because I cant use a small description for each part and I have to create many variables for the one part number to cover all the models it fits.

Plus wordpress will not allow me to use the same instance of the sku more than once so I am forced to ad a -1, -2, -3 to subsequent sku s to allow me to save.
This opens up another problem where the out of stock function is messed up from the weird sku s

hoping someone can advise or suggest a different method of adding product.

cheers and thanks in advance