What it's give you there is the amount you'd have to upload to be able to recover the entire file even if 10% of the file was corrupt (around 217MB). I suspect we have much less corruption than that so I doubt we'll need anywhere near as much.
Okay. Here's a quick guide on how to build Par2 files.
1) Run Quickpar
2) Click on the Add Files button. (I've added Sparky_fs2.vp you should use the freespace.zip (or whatever was the corrupt one) from ShivanSPS's pack)
3) Leaving the other settings on default should be fine. The only one you need to care about is the Number of Recovery blocks. In the example I've generated 21. That's probably about all you should make. If Roach needs more than that a new source is what is needed. This is really just about fixing minor CRC errors.
You should now have a screen that looks like this
Your settings may be somewhat different but that really shouldn't matter.
4) Click on create and the PC will go to work making the parity files.
5) What you'll be left with is 5-6 files in the same folder as the Freespace2.zip file
The first one is the one that tells you how much you need to recover the file. So upload that one at least. Roach need only download it and click on it to be told how many blocks he's missing. If it's under 21 upload all the rest of the files, he downloads them and can simply click on any of them to repair his file.