Please help with icons!

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90KB, 326x600px

I've never really had the courage to ask, but it is getting rather critical!
Please help!

I want to combine two sets of icons! Of one set of icons, I wish to use only the application and folder icons! Of the other icon set, I wish to use everything else! Additionally, I wish for them to inherit from where they used to inherit!
For example: if an app icon is missing in the icon set I wish to use for app icons, it should borrow from the icon set it would have originally borrowed from, and when the battery icon is missing in the other set, I wish for it to borrow from where it would have borrowed from!!!