ok your build in post 1 looks good, i see nothing wrong with it except im a little confused @ 16 X 0.5m cables ?
but yh all parts seem good and i think your wise to stay away from a rack server there over rated jus a normal box will do.
and its wouldnt be etirely neccessary to go with server parts how cool cpu's run nowa days it might be worth looking @ a low end c2d that way u have better compatability with the motherboard and but a good hs&f and it will be absolutely fine.
Hmm... I realise that, but i have just found out that the budget is £1500-2000 - I may had well build a very good server!
The *16 ethernet cables are for the switch, BTW