I don't quite get the new motherboard. Going from a good Asus board, to a (imo) lesser motherboard from ASRock? I haven't played with either board, is there settings restricting FSB on the ASUS?
I'm wondering why you don't have any overclocking room - I don't know your settings in bios, but perhaps you're clocking your FSB higher and your board isn't posting because your ram is standard 800Mhz?
You would have to move up to faster RAM in order to clock the FSB past 200Mhz.
I would throw some 1066Mhz DDR if that's the case, i'd recommend some GSkill:
http://ncix.com/products/index.php?s...acture=G.Skill
You can PM that RAM to $95.
I don't have any experience with a Scythe Mugen 2, however I do recommend the CM Hyper 212 for just about anything.
http://ncix.com/products/index.php?s...e=COOLERMASTER
You can pricematch to around $20.