How to transcode mpeg to prores?

From a client I got raw material to edit: 8 huge files, all MPEG, which won't load into FCPX nor Compressor 4.

Now what to do?

I have searched these forums and found hints to use a free programme MPEG-Streamclip, which tells me the following:
The Apple QuickTime MPEG-2 Playback Component is not installed...

Then it shows a link which doesn't exist anymore and leads to QT-pro. Really? I bought Compressor 4 and QT Pro still can handle more codecs?

Any help appreciated, thanks in advance.