MB+CPU for gameserver

Hi,

3 months ago I bought a server for some minor projects of mine, like a minecraft-server for my friends.
This is the hardware I used:
AMD ATHLON II X4 645
Asus M4A78LT-M
4GB Kingston ECC-NonRegistered-DDR3-RAM
60GB OCZ Vertex 2 (for system)
2x2TB Seagate momentus (for data, mirrored)

Never had any performance-issues, temperature never got higher than 60°C, so everything seemed good and it cost me less than 500€.
After 1,5 months the server started freezing without warnings from the system and now, 3 months after, motherboard and cpu are dead.
I got the feelings that those were not made for a 24/7-server-setting, so I'm considering to invest in server-components.
After a first look on the internet my impression was that I would have to invest around 400€ for those two to have similiar power like this:

AMD Opteron 4234 (6x 2.7 Ghz) (130€)
ASUS KCMA-D8 (250€)
16GB Kingston ECC-Registered-RAM (already got those from a friend)

Do you think with those components my system would be more stable? Or do you have other recommandations? (Powerconsumption is no point of interest)

There's no reason a system should fail after three months. I run my PC almost 24/7 even though it's not a server and it's been running since 2008. There's something wrong - you should figure out what it is before buying anything. You may even be entitled to a refund.

thanks for the hints.
@FinneousPJ: I think it's a difference having a pc or a server, e.g. on my server I get about 100 SSH-login-tries only because it got its own ip.
@JuniperSprouts: thanks a lot, this never came to my mind, never bought used hardware.

I found this for 300€:
IBM X3850 including:
4x Xeon MP HT 3.66 Ghz
16GB RAM

Do you think this would perform similiar to my current setting?
Also there is one problem, the built-in RAID-controller only supports SAS, not SATA but it says it has some free PCI-X so I think it should be possible to insert a SATA-Controller there or is this not a good idea?

thats the data of the processors:
Intel Xeon MP HT "Cranford"
FSB 667 MHz
3,66 GHz + 3,66 GHz Hyperthreading
16 KB L1-Cache each core
1.024 KB L2-Cache total
Single Core (SC)
Sockel 604
Incl. Cooler
There's also a version with 2 instead of 4 processors of this type and 4gb of ram for 85€. The point i am worried about are the small cache and FSB compared to modern processors.