X2 4200 65w or Opty 1212?

Been looking to upgrade my AM2 Sempron 3000+, and with my given budget I have two choices.

First choice around £100 is a 90nm 65w 4200+ X2 at 2.2Ghz. 2x512KB cache.
Second choice at £120 is the Opteron 1212 at 2.0Ghz. 2x1MB cache.

The PC is mainly used for gaming and video. Which CPU should I go for?
Will the Opty with the bigger cache run games faster? Or does it not make much difference?
Will he Energy Efficient X2 oveclock much higher since it should be able to take more overvolting?

What I'm after is potential stable overclock on mid range water, and higher gaming performance.

First issue is compatibility, unlike the S939 optys, there are a bunch of boards these don't work on.

Cache doesn't make a huge difference, around 5% depending on the application.

Also you might want to consider the 4000+ Brisbane, it can most probably do 3ghz+ with a good system around it.

My board is an Asus M2N32-SLI Deluxe, hopefully it shouldn't have a problem.
The 4000+ Brisbane sounds quite interesting. Anyone know where I can get one in the UK?

Here

or

Here

id recommend scan personally, but ives used eclipse computers they were trouble free also