How hot? X2 4800 problem...

Hi, I have recently assembled my new rig, the relevant parts consist of a custom made wooden box with watercooling, X2 4800, 2 7800GT factory clocked at 470Mhz, a ASUS A8N32-SLI mb. My water cooling i configured like this: cpu - gpu1 - gpu2 - pump - rad.

Now my question is about temperatures. My system is about 43C at idle and gets up to about 47C after playing for a couple of hours. I've read reviews of Graphics cards and those temps are pretty ok for a gc, but the cpu. My old 3700 san diego was 37 idle and 43 at load. Should I get a separate cooler for the cpu or will a 4800 likely get up to or exceed 47C at full load using a air cooler that doesn't sound like a vacumcleaner?

If I lower the fan blowing through the rad the system get unaudible but temps rise to 46 - 51C. Are those Ok temps for a system?

So my question is: Should I disconnect the cpu from the watercooling and get a good air cooler instead? If so, what cooler should I get that's silent but still good at cooling?

My other question is about the chipset temp of the A8N32-SLI, how hot can it get without beeing in danger? Right now I'm using the accessory fan with a voltmod making it pretty quiet keeping my system chipset at 34C. But If remove it the chipset get about 47C, is that ok or to hot?

Thanks in advance!