Urgent help needed with replacing motherboard.

Basically, I went for a shower, came back to my computer and my computer was turned off. I then pressed the power button but my computer didn't do anything, the power light lit up though. I then did other things, like unplugging it from the mains, leaving it to cool down, plugging it in different sockets around the house and no luck. Everytime I press the power button, it lights up but NOTHING works, there is no sound or motion from any of the parts, it's completely dead.

I phoned up PC world and they said it's most likely that my motherboard has died and it needs to be replaced. They will charge me £70 for the labour and I'll have to supply a suitable replacement.

I basically need to find a cheap replacement for my motherboard which will prevent me from having to reinstall the operating system and any files.

Here is some information about my computer:

Specifications & component details - http://support.thetechguys.com/layout.aspx?ID={73b2ec20-f990-4015-980f-1a2b5c2956f0}&CatID={b5098dca-429f-424d-9d46-68f2b41bc867}

Motherboard:
The exact model of my motherboard has been really difficult to find, however I believe, after opening the case, has the specs listed below.
Foxconn P48907MB 2.0 KRS2H

Summary
This article contains information about the San Francisco 2 (Foxconn) µATX motherboard.
Specifications
Network

* Realtek RTL8100C-LF.
* 10/100 Mbit.

Expansion Slots

* 1x PCI Express 16X.
* 1x PCI Express 1X.
* 2x PCI.

Drive Support

* 2 SATA connectors.

Form Factor

* µATX Form Factor.
* 24.4 x 24.4 cm.

CPU Support

* Socket LGA775.
* Single processor support.
* Supports Intel® Pentium® 4 Processor.
* Supports Intel® Pentium® D dual-core processor.
* Supports Intel® Celeron D processors.
* Supports Intel® Core2 Extreme processors.
* Supports Intel® Core2 Duo processor.

System Memory

* Two 240-pin DDR2 SDRAM DIMM slots.
* Dual Channel DDR2 400/533/667/800
* Supports up to 3GB RAM

Core Logic (Chipset)

* VIA PT890 + 8237A.

Audio Chipset

* Realtek ALC888.
* 7.1 surround.

That's all the information I have. I honestly need some serious help. I don't know much about motherboards.

Can someone find me a suitable and cheap replacement for my motherboard which will work fine with my computer so I won't have any problems or have to buy any other components?

And is it worth paying PC world £70 to replace it for me or is it an easy and viable solution to replace the motherboard by myself?

Thanks for the help in advance. I need this sorted out ASAP. I don't want to buy a new computer ;\