what kind of games, crysis no..... but with LFS its more than enough
and the E7200 can be overclocked to 5,3 Ghz, if you have some serious cooling
and i also have that videocard and i really like it, i have an intel E8400 3Ghz and i can play Crysis on high.
btw the prices of the videocard depend on the brand, it varies from 140 euro to 170.
5.7Ghz? There are probably only a handful of overclocking teams who have reached 5.7 Ghz and its most likely been run on liquid nitrogen which can't be used in every day situations, its only used for benchmarking.
The E8400 is a great option at the moment, not very expensive and is a very fast dual core near to the top end of what processors are doing at stock speeds these days.
I've just noticed you want to experiment with movie making..My rig is probably around the same if not worse than yours Chris and I do a lot of video editing with video footage and game recorded footage, check out the movie making tutorial in the LFS Manual (link at the top of the page) for some tips on getting the most out of your current system. I don't think you really need to upgrade if you want to edit.
People say you need a good quad core to use proper movie editing packages, I use a 2.8 Pentium Dual core (Core 2 Duo, just branded as Pentium) and I can edit using the top suites such as Sony Vegas and Adobe After Effects with no problems at all.