Upgrade Advice/Suggestions

Hello,

I'm thinking about some upgrades - I think it'll end up an entirely new system

I'm currently using my HTPC for all PC tasks which consists of

HD5770
Wolfdale E8400 C2D @ 3ghz
4GB RAM


I've brought my old PC from my old home finally, but it's knackered...

Orignal Coolermaster CMSTACKER case.
1000w Enermax Galaxy PSU
Thermalright XP-120 Extreme

That's probably all that i'll be keeping from it.

I play games like Mass Effect, just started on Skyrim and still play CNC3 - Kane's Wrath. I'm always open to new titles - but that HTPC spec seems to play them all fine on my Dell 24" @ 1920x1200 (16:10 FTW)

The HTPC needs to back in my AV unit, but I seem pretty happy with the spec considering it plays the stuff I want to play at decent quality. I want my new computer in the CMSTACKER case to be able to play any/all games at max detail at 1920x1200 while encoding blurays into mkvs at the same time - I don't want the machine tied up encoding all the time. I dont care how long it takes to encode... I assume a 4 core cpu will be needed. I don't know about GPU encoding so maybe someone can enlighten me if that is a better option?

The most important thing will be that this system needs to be whisper quiet. I've done watercooling in the past and i'm not interested in it, I don't overclock either. But I able to install gpu heatsinks for whatever card if it means silent/cool operation.

Budget - well, mobos and ram are cheap at the moment, ideally around the £300 mark for a cpu and g/card, I can budget for the mobo and ram seperately.

thanks! and sorry for length