Does anyone have any means to brute force a .cap file?

This is a test for me by a friend but my PC isn't fast enough to do this!

I was thinking about renting a super PC for a few days but I cant find anything online where I can do this easilly.

I'm willing to donate to the forum if anyone can help?

Maybe there are fully compiled rainbow tables up to say 12 characters? If so any advice would be helpful as I have no idea how to use them!

(I've tried many dictionary lists etc)