Hi, the card will not work between the two, compare the connector in these 2 pics...
There are cheaper options if Wifi was the only problem...
The PPC Mini could share iTunes, but not use the latest versions, or Airplay, or many orher modern Apps.
The hard drive from the Intel Mini could be used in an external case, or possibly with a Sata->IDE adapter, but that'd be a tight fit.
All in all, I don't think it's what you want.
I feared that kind of incompatibility (it didn't occur to me to search ebay for the parts...)
And I guess you're right: it's too complicated and limited. I was just trying to find some use to those once useful machines... (and I really would like to have some practical solution to play songs in my iTunes library, without the need constantly connect and disconnect my iPod)
I guess that there are some easier solutions.
Thanks a lot for your help.