[Foundation-l] Using content from Wikipedia

[Yorian]

Hey everyone, I have a question I'd like to ask:

I have an idea for a (hopefully profitable) website, and I'd like to use 
content from Wikipedia for it. About half of the content from the 
website will be from Wikipedia. Of course I will mention Wikipedia as a 
source and I will donate some of my profits to Wikimedia, but is it okay 
to have other content on an individual webpage, besides the 
Wikipedia-content, that is not GFDL-licensed? The GFDL is not very clear 
on that, and people on the Dutch and English Wikipedia couldn't answer 
this question. Is there anyone who knows this? I'm afraid I can't afford 
a lawyer :( Thanks in advance!

Yorian