How to exclude items of type 'product-kit'

Hi all,

the scenario:
- I have a couple of individual products (sold at their full price)
- I have also a product-kit which contains all these products (sold at a discounted price)
- "Normal" customers are able to buy either single products or the full bundle
- I have a user role "reseller" set up, for which a reseller discount is applied to all products.
- BUT: I want to prevent users with role "reseller" from purchasing the already discounted bundle, meaning the reseller-discount rule should not be applied to produkt-kit items.

I tried two different things:
1. Have the discount only apply to 'products', not 'product-kits'. As I understand it, only filtering by product-class is currently implemented. So this doesn't seem to be possible. Right?
2. Set up the discount condition in such a way, that it only applies the discount when the customer purchases a specified set of products (IF cart contains [1xItemA+1xItemB+1xItemC] THEN apply discount). The idea is that I could then remove the pre-set discount from the bundle and have the bundle discount applied via a discount rule set to exclusive, which solves the problem with the reseller discount. I tried the multi-product condition, but no success. I'm not really sure how this condition is supposed to work.

Any help would be greatly appreciated!