Where can I get a wifi chip for my iPad 1?

I know I need to replace my wifi chip as the wifi option is greyed out. Seems to be a common fault in the ipad1.

I need the Broadcom bcm4329 chip to replace my faulty one but who knows where you can get one?

Nothing on eBay or found on google.

Does anyone know if you could replace with an iPad 2 or 3rd gen chip as well and if so where you can buy that Broadcom wifi chip ? Has anyone replaced the chip successfully?

A second hand iPad 1 is £185 so surely there is a parts supplier, it's not rocket science opening them up.

Thanks to anyone who can help and provide a working answer to the above - massive kudos and points!