Can I make attributes linked products?

Hi guys and gals.
I sell some bath and beauty product gift boxes. I want to make them customisable so the buyer picks which bar of soap goes in, which bath bomb goes in, what style box they want.
The soaps and bath bombs are also sold separately on the site. Is there a way to make the products themselves an attribute in the gift box listing so that when someone picks a box with say "Lavender soap" in it, the Lavender soap stock goes down 1? Like it would with linked products?

I don't think I explained that well but any help would be fantastic.

Look in the free add-ons for "Stock By Attributes"

Thank you :)

Either I didn't install it properly or it doesn't work with 1.5 :(

Instead I've put the products up with out linking them and will have to edit the stock on the items when one sells.

I have another problem now though lol. This is the product http://darkboutique.co.uk/fill-your-own-gift-box-p-568:07d46474e5275028e09312e7d1bac22d.html and I would like to show a total price before the customer adds it to the shopping cart BUT I don't want it on the drop down box. Maybe a total above the add to cart button?

Is this possible?